Double-Whammy Look At The Pentium 4 157
SystemLogicNet writes: "We at SystemLogic.net have just taken a technical look at the Pentium 4 architecture. In the article we go over all the basics that all the other sites cover like the double pumped ALUs, iSSE2, the longer pipeline, etc, but in addition we have some discussion about how different program structurings have an impact upon the design, and performance of the Pentium 4. One of the major areas where this comes into play is how complex data structures interact with the underlying philosophy that the Pentium 4 is built upon -- extreme bandwidth. This Pentium 4 technical background can be read over here. At the same time, we've done a rigorous analysis, including benchmark description and discussion regarding the Pentium 4's performance, and this can be read over this way."
Testing of P4 1.7 to AMD 1.1 completly bogus (Score:1)
Re:When will reviewing the P4 become old news? (Score:1)
Did anyone else notice? (Score:1)
Sheesh - go down to your local computer store and get a 1.4 GHz Thunderbird at least - it'll only set you back less then 200$.
Anyhoo - I think given the actual mhz difference the Thunderbird does VERY well.
Re:Did anyone else notice? (Score:1)
Why they're centuries ahead of the powerful K6 233mhz.
Hey lets do a dual cpu benchmark: Dual Athlons compared to Dual P4's, oops MP P4's dont exist, doh!
It is early for the Pentium IV (Score:2)
It is a little early to begin reviewing the Pentium IV. Intel released it early due to market pressure from AMD.
When the
What a joke... (Score:3, Insightful)
Tom's Hardware Guide [tomshardware.com] or AnandTech [anandtech.com]
Sorry, but comparing a 1.1gig/200Mhz FSB Athlon to a 1.7gig P4 is laughable at best. What hardware review site uses a processor that's over a year old (Athlon 1.1gig/200FSB) in a comparison to one of the latest processors from the competition?
In other news (Score:4, Funny)
Using the new process of W.attage H.alting R.esistance E.ngineering, Intel can reduce pent-up system tension at an even lower cost.
Also, the WHORE system is fully compatible with the C.omposite R.ecursive A.lgorithm C.reation K.it used for extreme overclocking.
"The CRACK/WHORE combination should be a killer setup for many of our users, and we have already had several U.S. senators make inquiries" says John Thompson, head of engineering at Intel. "We even allow for massive clustering with the P.arallel I.nsulating M.ultipartite P.olymer, or PIMP management process.
Thompson also spoke of project BITCHSLAP for correcting wayward systems, but could not elaborate on it...
One Quick Question (Score:4, Insightful)
I sure hope you Slashdot isn't selling Front Page space to any little company that pays...
Re:One Quick Question (Score:1)
skewed graphs to favor intel (Score:5, Funny)
also, note that the 1.7 ghz p4 has a 600 mhz advantage over the 1.1 ghz athlon and usually the performance difference was only 10-40%. the p4 has over 50% more processor mhz than the athlon. what an unfair comparison, especially when the 1.33 ghz athlon is out and available for purchase. processor mhz for processor mhz, the athlon beat the p4.
Re:skewed graphs to favor intel (Score:1)
Clock speed disparity is the point. (Score:3, Insightful)
The point of the extremely long (20-stage) pipeline of the Pentium 4 is the ability to reach extremely high clock speeds - much higher than the Athlon could ever reach. Of course, Mhz-for-Mhz, the Athlon is going to beat the Pentium 4 performance-wise, but it wouldn't tell us anything except the obvious differences in the two's design philosophies.
Re:Clock speed disparity is the point. (Score:1)
Today on pricewatch, the 1.1 Ghz AMD processor costs $77, the 1.4 GHz $154 and the 1.7 Ghz P4 costs $324. Today I can put together an AMD based system using the 1.4 Ghz Athlon that will perform roughly the same as a 1.7 (or 1.8) Ghz P4, at 1/2 the price of the P4 machine. For most rational folks, the choice is obvious.
Re:Clock speed disparity is the point. (Score:1)
Re:Clock speed disparity is the point. (Score:1)
amd 1.4 ghz is available and kicks butt (Score:3, Informative)
Here is a june 6 pcworld review [pcworld.com] where an amd 1.4-GHz system is "the fastest system yet tested by PCWorld.com" beating out 5 systems based on the 1.7 ghz p4.
Here is a tech report review [tech-report.com] of an amd 1.33 vs intel 1.7 where they conclude: "Intel's new entry, the 1.7GHz Pentium 4, performs about like a 1.2GHz Athlon in most situations."
You cant get duel [amdzone.com] processing power from a pentium 4 like you can with an athlon.
Re:amd 1.4 ghz is available and kicks butt (Score:1)
Maybe you meant "dual." Wish people could spell.
Re:skewed graphs to favor intel (Score:1)
However, the skew was disgustingly pro-intel.
Anandtech had reviews of the 1.1GHz Athlon _11_ months ago, and modern variations of Moore's Law tell us a lot about periods that long.
Also note that the Athlon chosen was using previous-generation memory technology.
I want to see a Q3 2001 AMD result, i.e. 1.4GHz/266MHz DDR. Anything else is a con.
FP
Re:skewed graphs to favor intel (Score:2)
Re:skewed graphs to favor intel (Score:3, Interesting)
For christ's sake. The P4 is using pc800 RDRAM and a 400 mhz FSB. (100X4) The athalon is only running a 200mhz FSB and PC 133 SDRAM!!!
I mean, lets be realistic, here, folks. The P4 has a 600 mhz clock speed, 667 mhz ram clock speed, and 200 mhz front side bus advantage.
on pricewatch, the P4 1.7Ghz $326, 128MB PC800 is $44, and a P4 Mobo is $115.
By comparison, a 1.33Ghz Athalon is $120, 128MB of DDR is $17, and DDR boards are $94.
P4 = $485, Athalon = $231
Add to the other advantages the $254 price advantage (more than double).
Anyone say the test is fair, or that the P4 is a good deal?
me either.
~z
Why the Pentium 4 sucks. (Score:1, Redundant)
Re:Why the Pentium 4 sucks. (Score:1)
Thanks for posting the Emulators, inc. link. It's a great article and I had lost the bookmark.
Re:Why the Pentium 4 sucks. (Score:1)
Re:Why the Pentium 4 sucks. (Score:1)
It breaks many of the code optimization tricks that us assembly language programmers have used for years. In turn this shows up as a decrease in performance in things like device drivers which tend to contain more assembly code than most applications, and it will shows up in slower execution speed of compiled applications, for example Windows and Linux applications written in C++.
That guy has some valid points, from his limited point of view that is. However, what he regards as a crime from intel is in fact intel's biggest and probably best step. Ditch the legacy crap.
Benchmarks show that programs compiled with intels compiler using P4 optimisations, beat the crap out of the competition - including T-birds.
Re:Why the Pentium 4 sucks. (Score:2)
What goes through the mind of vendors who assume that customers will, of course, run out and replace all their software to take advantage of a new chip.
This sounds all too much like the music industry who thinks we'll run out and buy new copies of stuff we already own in order to enjoy some new technological advance.
I'm sure the P4 will be great... in a couple of years.
Re:Why the Pentium 4 sucks. (Score:2)
That's predictable. A code recompile is needed with every one of the Pentium processor generations in order to make any significant performance gains. I'm not saying that's good or bad, there are downsides and upsides to that. For one, we'd get faster code but that means that the compilers have been re-tweaked and all our software is re-compiled, but then that usually means waiting for the next revision, and buying new software.
The link claimed that the optimizations available in modern compilers aren't much beyond Pentium.
Re:Why the Pentium 4 sucks. (Score:1)
Re:Why the Pentium 4 sucks. (Score:2, Insightful)
1) He's writting in assembly.
Any change that doesn't rely on x86 basics he's grown to love will likely be considered by him as bad. Eg. "... and even went so far as to expect developers to rewrite their applications to make use of the Pentium 4." The assembly language programming paradyne that he has embraced is not as conducive to rewritting so it's a chore. If he was writting in C and using asm for the most preformance intensive functions as is now standard practice for the non lazy (who know their target platform and optimize for it)it would not be such a chore. Perhaps if he used an Intel compiler plugin that optimizes for the P4 he would not be complaining. Should he have to do so? Nope, but it seems to be the way everything is heading whether you look at AMD or Intel. Also with AMD embracing functionality of SSE2 on their newest processors this is not going away.
I love asm, but most people would not try to write a modern office suite in it. It's a shame but it's the way things are. I wish more programmers of commercial applications coded better but I don't think this is going to get resolved anytime soon, unless we move more to an appliance architechure where resources are both well defined and limited or go opensource. I'm not holding my breath.
2) It sounds like as an early adopter he got burned on price. There was a time (11 months ago?)where the p4+rdram was about 3.5 times the cost of an athlon+sdram. If you look at the present it's more like 2.1 times the cost for a p4+rdram vs an athlon+ddr memory. That is still a sizeable chunk but remeber the cpu and memory just part of the equation. There's still case,ps,motherboard,storage and yes the OS and productivity license which despite being in a Windows dominated world is likely to be the first thing cut to save costs. It's already happened on the low end and the highend, and I think it's only a matter of time before it happens on the mid end.
As a side note it's interesting to once again hear the arguments for and against thermal protection. I think the arguments both have their points, but I think it would be better to have it, but also be able to turn it off from the BIOS. AMD's new chips will have the integrated thermal diode so really the issue is will endusers be to easily configure it manually.
Upcoming AMD technology. (Score:2, Informative)
While I agree that as technology moves forward the traditional ways of X86 programming will have to expand along with the technology, and in some areas change completely, I'd just like to share something about upcoming AMD technology in this regard.
The next-generation chips from AMD are being designed with programming optimizations done at the firmware level. For example, a FORTH interpreter is being ingrained into the preprocessing area on the chip die itself. This makes it easier not only to add firmware-level software like BIOS, bootloaders, etc more easily, without resorting to running the code through a compiler into X86 instructions and machine code, but it will also make it much easier to write more optimized C compilers (and other compilers for that matter). If you combine this with the improved instruction technology that AMD will be incorporating, it makes for a very powerful new platform for all programmers.Dwain Snyders
Research and Development, AMD
Re:Upcoming AMD technology. (Score:1)
Could someone please tell me... (Score:5, Funny)
Kjella
Re:Could someone please tell me... (Score:2)
The way you describe it doesn't seem to fit with how the words are usually used.
Usually in sales & marketing, the term is mid _range_, mid _end_ is simply rediculous as even if the middle had an end, it's not descriptive as to what the end of a middle is, or which end assuming if there is one, or where that end is if there was only one.
Re:Why the Pentium 4 sucks. (Score:3, Funny)
Damn... that's the first time I've seen someone who programs in C/C++ tell someone who programs in ASM that he's lazy. What balls, man! Way to go!
Misleading graphs (Score:3, Interesting)
Some only differ by a few percent, the lowest about -4.5% of P4 score, yet the distance represented on the graph would suggest nearly a 60% difference or more.
This review site needs to get a clue about statictics and start using proper graphing according to real differences, not magnified margins.
Re:Misleading graphs (Score:5, Informative)
The graphs were a mistake that was made in Excel...I have fixed them and uploaded them where they start at 0 (I'm the writer of the review). You can see an explanation here:
http://www.systemlogic.net/boards/showthread.php?t hreadid=1404 [systemlogic.net]
Re:Misleading graphs (Score:1)
Seriously, though, god knows what other mistakes were made in these crummy benchmarks.
I want my DDR!
Re:Misleading graphs (Score:2)
The 1.7 was released april 23.
The 1.333 Ghz 266 fsb athlon was released april 1.
The MSI KT7 Turbo is at best a middle of the pack Motherboard. It does not use DDR.
The intel 850 is the best platform available for the p4
This is sort of like saying the ford mustang (P4) is faster than the chevy camero (1.1;200,KT133), therefore it is faster than the corvette(1.333;266AMD760). WRONG
BAD BIASED ARTICLE NO COOKIE! LOOSER INTEL SUCK UP PAID FOR JOURNALISM.
or a fan boy, therefore unpaid suckup double looser stoolie.
-1 flamebait
The P4 Blues... (Score:2)
1. The P4 1.7G is a faster processor than the Athlon 1.1G (and probably the 1.4G but they really can't say).
2. It costs a few hundred bucks more.
3. Just wait till next year's model, which will be even better.
It seems to me that the people who want the highest performance will pick up the P4, and those who want to save money will pick up a Celeron. Who would buy the Athlon? People who want to compromise between price and performance.
As for the temperature slowdown switch, I'm all for it. Why fry my processor unnecessarily?
Re:The P4 Blues... (Score:1)
Re:The P4 Blues... (Score:1, Interesting)
As for the it costs a few hundred bucks more, it makes a difference especially when your competitor is a few hundred bucks less AND making inroads into what was traditionally your turf.
"Just wait till next year's model, which will be even better." I think we all hope this is true, but it might not be. Both sides have stumbled at various points along the way.
As for the buyers. They will buy a Duron at the low end or even an Athlon. Why buy a Celeron when a Duron gets you more preformance, costs the same, and lets you upgrade to a faster processor and isn't a complete dead end yet? Even the big companies are advertising them in the local newspapers.
Re:The P4 Blues... (Score:1)
Even if Intel does ramp their procs up to 2.5gigs, with the i845 chipset coming out (PC133/DDR SDRAM) those procs are going to fall flat on their faces.
RDRAM is what gives the P4's their edge. Once that's gone (and most consumer level machines WILL use the i845 because it's cheaper), you're going to see Intel in a world of hurt when it comes to performance.
Unless Intel makes some changes to their processors, or a faster DDR SDRAM technology comes out, you're going to see some serious ass kicking being done by AMD.
Pentium 4 is a bomb. (Score:2)
On the other hand, the Athlon and its offspring seem to be better no matter which way you cut it. You'd think they'd keep intel on its toes...
A bomb or The bomb? (Score:1)
Re:Pentium 4 is a bomb. (Score:1)
I had a duel Pentium Pro machine. Truly a kick-ass machine.
Scathing! (Score:1)
bashes that hard on a product/company I get
suspicious of their data.
But in this case, I believe it. I've been madly
in love with AMD's Athlon/Duron line since I first
tried it. I upgraded all my employers PC's to
Duron processors (the day-to-day performance diff
tween Duron and Athlon not even noticable).
The dnet client on an AMD Duron/Athlon will whip
any Pentium hands down, clock-for-clock.
I do believe Intel really shit their nest this
time.
Re:Scathing! (Score:1)
4 sucks" msg, re: the url
http://www.emulators.com/pentium4.htm
optimized for Xtreme Programming? please. (Score:2, Informative)
I love XP (Score:1)
Whoa there! That is the best feature of the chip! Once XP catches on (remember OOP 10 years ago, vs. OOP now?) Intel will have secured themselves a leg-up on the imposter brands.
Re:optimized for Xtreme Programming? please. (Score:1)
Re:optimized for Xtreme Programming? please. (Score:1)
Re:optimized for Xtreme Programming? please. (Score:1, Troll)
If you don't know this kind of stuff, then don't criticize Intel. Branch Prediction is hard stuff. If I asked you to do it with 90% accuracy, I bet you couldn't.
Re:optimized for Xtreme Programming? please. (Score:3, Interesting)
Actually, it's not exactly "hard" stuff from an implementation point of view. Cycle times are short so you want a predict equation that you can do quickly and in one cycle. In fact, you can get pretty good results with a simple 4 state strongly not taken (00) - weakly not taken (01) - weakly taken (10) - strongly taken (11) saturating counter that updates when a branch is confirmed to be taken or not taken. If your BHT (branch history table) is sufficiently large, you can get decent results. Sprinkle in some voodoo magic by adding a GHR (global history register) which hashes the opcode address based on the state of the last n taken branches and you can get a couple of extra percentage points. I've seen upwards of 95%-97% prediction rates with such implementations but that's in a RISC environment which also provides fairly accurate branch hints in the opcode itself (much like the Itanium does). (The compiler knows what the code should do and what the semantics of a branch are: an "if", "for", "switch" construct, etc.)
Where things probably get weird for Intel is that their BHT probably suffers a bit of address aliasing/underutilization due to the fact that x86 opcodes are variable length. With RISC architectures (fixed length opcodes), you can chop off the last couple of address bits since the 0,1,2,3 cases don't matter == less address aliasing over a greater range of addresses.
Mispredict bypass buffers are another nicety that help back out of branch mispredicts because you don't have to go running back to the I$ and wait two cycles. In fact, while you're going down the codestream for the "predicted taken" path, you can also load up the "not predicted taken" path into a line buffer from an alternate cache such as a BTB (branch target buffer: if the data is available, a TLB entry exists, etc) and bypass the 2 cycle hit on the I$ on the mispredict. Two cycles are two cycles...
Engineers have a very big bag of tricks to work from..but they do have to know when to cut the apron strings and say "out with the old, in with the new." I think the key to major ramp-ups in speed for the x86 architecture is going to be when Intel proclaims "The Great Simplification" (a la "A Canticle for Leibowitz") and deprecates a whole slew of ancient modes (e.g., 286 type stuff) such that they must be emulated through an OS trap. By that time, DOS based OSs like W9x will be about as common as Win311 is now so it won't even matter. About the only people who I can see complaining then are VMWare, Netraverse, Plex86, and the WineHQ Team.
Re:optimized for Xtreme Programming? please. (Score:1)
Good marketing campaign... (Score:3, Funny)
I can see the ads now..... "The Pentium 4 - Because our Pipline is bigger than theirs!
Size Doesn't Matter (Score:1)
(They're also lying..)
Re:Size Doesn't Matter (Score:1)
Intel is struggling (Score:2, Informative)
Man what is up with those graphs? (Score:1)
Re:Man what is up with those graphs? (Score:2)
People are missing the big picture (Score:2, Redundant)
I agree that the P4 is not the best CPU at this time. However, Intel has designed this new architecture looking out 10 years or so. Many of these choices are dictated by the laws of physics, and all other processors will be heading this direction over time.
The fundamental problem is that propagation speed of a signal on a chip is essentially fixed (that's why the minor improvement from a special trick like copper wiring was a big deal). As you speed up the transistors, the signal propagation delay becomes more of a bottleneck.
To avoid this, you have to break the logic steps into smaller pieces that live in a smaller portion of the chip. The standard way to do this in synchronous logic is to pipeline the work into more stages. The total signal propagation delay to do one instruction remains about the same, but at least you can pipeline alot of instructions to try to get more work done.
This processor is not very competetive today, but in 5 years there won't be any other way to make forward progress. By that time, Intel will have worked out the kinks (problems with branch prediction, memory interface snafus, etc.), and this core will probably be as wildly successful as the Pentium Pro/PII/PIII/Celeron core was.
BTW, remember how sucky the Pentium Pro was when it came out? It was a piece of crap on 16-bit code and it would generate huge pipeline bubbles for no good reason. Over time, they fixed these problems and made countless $billions in the process. Watch for a repeat with this new architecture.
Re:People are missing the big picture (Score:1)
That's all well and good, but how does this help me right now? I want to buy a computer today. What should I buy? A Pentium 4 which might or might not become worth something years ahead down the road, or an Athlon which I _know_ is good _today_. Future forecasts may be fun to do, but they don't do anything for immediate purposes.
As for the Pentium Pro, Intel didn't have a real competitor at the time. Today, AMD is serious trouble for them, so they can't afford to simply sit back and tell the customers to wait 5 years.
Re:People are missing the big picture (Score:2)
I was just trying to explain some background information for all the people who keep posting "1N73L 5UX5 -- 4MD R00LS" all the time, so they won't be confused when Intel doesn't go out of business next year.
Re:People are missing the big picture (Score:1)
The previous poster is not trying to suggest that the P4 you buy today will magically become a better chip in 10 years, he is arguing that the P4 architecture is designed for the future and that it will r0x0rs, given time. But that won't do anything for the chip you already bought. Get an AMD if you're buying now, compare again if you're buying in 5 years.
Re:People are missing the big picture (Score:2)
The Pentium 4 is an inferior chip right now, so it's a poor purchase choice, again, now - and for more reasons than are made evident in this comparison.
puhleeeeez (Score:1)
Re:People are missing the big picture (Score:1)
Re:People are missing the big picture (Score:1)
Dropping RDRAM and going backwards to PC133 memory is going to seriously kick P4 processors in the nuts.
Re:People are missing the big picture (Score:1)
This gets into a structural problem with the PC industry. All the real profit in the system is made by the CPU manufacturers and Microsoft, and therefore they are the only ones doing significant R+D work. Everything else in the system is tagging along. (Well, the disk drive people have made huge accomplishments, but it sounds pretty much like a break-even business.)
It still is sorta dishearting to see a retail store sell a superduper 1.5Ghz Pentium IV system with a crappy disk and crappy video and a crappy monitor and not much memory, and lots of MS shovelware.
Re:People are missing the big picture (Score:1)
It is as if people are lab testing Lamborghinis, but all roads are dirt or cobblestone.
The other thing (that you don't mention in your thoughtful analysis) is the software end of the deal. WTF are people doing with the computational power anyway? Fast CPUs bottlenecked at disk or bus, super vid cards...for what apps? I still don't see anything that even tests my DURON chip overmuch.
The high-end (media processing, content developers) users who NEED max performance may not even find single-CPU systems adequate at all...For true utility, we have to look at the ACTUAL goal for product usage. I think we find there is very little value for most users in anything over a 700m Duron or even 500+m PIII...
A 1.7P4 or 1.3Tbird, on a solid board w/ Raid drives (or SCSI)...that's for geeks, (the kind of rabid techies whose
And remember, people use 50" flat panel hdtv-capable screens to watch Rikki Lake and Survivor, so the waste is not without paralell.
Re:People are missing the big picture (Score:1)
Re:People are missing the big picture (Score:2)
How many people here actually have a P4? (Score:1)
using my P4 1.7GHz to play Tribes 2 under
Win2k and it's super smooth.
I've never heard anyone who has a P4 complain
about lack of performance or stability.
AMD chips are great but their mother boards
aren't that great due to the reversed
engineered AGP implementation. I have an
Athlon that's gathering dust because the
motherboard was a choke point in performance
and reliability.
Re:How many people here actually have a P4? (Score:1)
I've never had any complaints about the speed or the price of an Athlon system. I've heard complaints about the stability, but it's hard to take many of those complaints seriously when there are so many people out there who don't know how to build an Athlon system properly (using crappy power supplies, cheap RAM, etc.)
I've built and used many Athlon platforms. They are as stable as you could hope for on any of the popular platforms (Windows 95/98/ME, Windows 2000, Linux)
Sorry, but I have seen no evidence of what you claim is a "choke point in performance and reliability" ever
Re:How many people here actually have a P4? (Score:1)
AMD chips are great but their mother boards aren't that great due to the reversed engineered AGP implementation. I have an Athlon that's gathering dust because the motherboard was a choke point in performance and reliability.
Interesting. This machine is equipped with A7M266 & TB 1200/266. It's been rather stable:
uptime
8:52pm up 127 days, 2:22, 27 users, load average: 2.06, 2.07, 2.08
A choke point in performance and reliability indeed...
Intel needs a wake up call (Score:1)
This is no way to properly run a business, and now with amd's big pushes with their Athlon chip, they are being hit hard. With amd biting Intel's heals and making major headway, you would think Intel would wake up and smell the coffee( mmmm coffee). But they are still just designing rather non-innovative chips that are not really putting up a big fight against amd's Athlons. The p4 are still considered expensive, and still are being soled mainly with the rambus (bs chips) ram.
I am actually hoping that amd will push there Athlons to higher ghz speeds soon, so that we can see a true 1.7 ghz Athlon vs. p4 1.7 ghz. Or say at that time 2 ghz vs. 2 ghz battle. That might be able to wake up Intel. But we have to wait and see. What I really would like to happen is to see a real processor war. At this point, there is only Intel getting beaten down bit by bit in the 32-bit pc market. But I guess we will have to wait and see.
My 2 cents plus 2 more
The Technical Overview (Score:1)
"This means that the higher levels don't have to experience a cache miss before moving to the data in the second array, while the 32-byte-line design would! This has the benefit of greatly decreasing average memory access latencies for contiguously used data!"
I have honestly never seen anyone more excited about CPU Caches.
From what I can see (Score:1)
I think the article makes two very good points:
Note to David Pitlyuk and Paul Mazzucco: Big Blue outperforms the top 486 in every benchmark too.
Re:Sad state of affairs (Score:2)
Re:Sad state of affairs (Score:4, Insightful)
Umm... This isn't a very good analogy. Imagine instead:
Re:Sad state of affairs (Score:2, Insightful)
That is a much better explanantion, and now in respone to the original comment: it is nearly impossible to criticize that "miss rate" without actually going through the design process.
Something like Patterson & Hennessy would explain the classic tradeoff well. If you make a lower miss rate (imagine 9.5 out of 10 are hits), the time for hits goes up slightly. Now the main question becomes, what is the "common case".
The most important thing before you whine about some processor is to know the design process. Is missing 1 out of 20 times (but hit-time taking twice as long) better? Is missing 1 out of 7 times (but having a lightning-fast hit-time and tolerable miss-time) better? As a /.er there's really no room to say "thats so bad" unless you actually sat at Intel/AMD, went through the design process, and there was a better option for your mix of instructions.
Re:Sad state of affairs (Score:1)
Shame on both of you.
Better analogy: You double click on a Word file. It fails, because Microsoft can't build a halfway decent OS - it has NOTHING to do with an incorrect branch prediction.
Wrong branch taken: the correct instruction is fed into the pipeline a tiny fraction of a second later and you're set.
I recommend any book on processor architecture.
Re:Sad state of affairs (Score:1, Informative)
*Bzzzzt!* Wrong. Accurate branch prediction is expecially important when you're dealing with the P4's whopping 20 stage pipeline. Each incorrect prediction costs quite a few clock cycles and slows down overall processing signifigantly. See this [arstechnica.com] ArsTechnica article for details.
Re:Sad state of affairs (Score:1)
Re:Sad state of affairs (Score:1)
Wow, Intel really loves the MHz wars. Pumping out MHz when only 90% of the brancing is correct. Most of you probably think 90% is good, but think of it this way: 1 out of every 10 times you try and click on something, or double click something, or open a file, whatever, it fails. Every 10th Word file fails. This is good? Industry servers are designed for 5 9s (99.999% uptime), yet we can accept a 10% fail rate for our processors?
Maybe you should get informed what branching means.
Re:Sad state of affairs (Score:3, Informative)
Personally, I don't agree with the Brute Force methodology by Intel; I prefer simpler, cleaner and more elegant solutions. It is difficult to deny, however, that the brute force method has worked so far. Yes, yes, I know that the "x86 suxx0rs" crowd is now going to come out of the woodwork. Let me just say this: It may not be the best architecture, and it may be kludged for backwards compatability, but... it works, and it's cheap. With any luck, the 64-bit processors will be able to buck the trend of backwards compatability (has anyone heard anything about this with regards to Itanium and/or AMD's 64-bit chip?).
Re:Sad state of affairs (Score:1)
Re:Sad state of affairs (Score:1)
Re:Sad state of affairs (Score:2)
Re:Sad state of affairs (Score:2)
Re:Sad state of affairs (Score:2)
You see, a 90% prediction rate is incredibly bad (I don't even know how they managed to get that low, if the parent was correct with their numbers). Having to stop executing while waiting for a comparison is exceedingly bad - depending on the comparison, it may even have to do a memory read (!), and in all likelyhood, at least a cache read; neglecting the time for the comparison itself, which is usually a subtract and a bit check. Merced (I refuse to call it "Itanium"
I really hope that 90% number is incorrect - that's a pathetic number for a college CPU design course to get, let alone for Intel to get..
-= rei =-
Re: (Score:1, Redundant)
Re: (Score:1, Offtopic)
Re:Sad state of affairs (Score:1)
Oddly enough, most Windows users don't seem to mind...
Re:Ahem.. (Score:1)
Re:Ahem.. (Score:1)
This review is about three months late, and a couple hundred megahertz short.
All the major hardware sites have already done the 1.7gig, and actually compared it to a modern AMD processor. This site was a joke! What are they, bums in Silicon Valley doing hardware reviews for change?
Who can't afford one of the new AMD Athlons? Who CAN afford one of the new P4s?
Re:Ahem.. (Score:1)
Read the review before you make comments like this, because aparenly you didn't.
Re:Ahem...back to ya (Score:1)
If you weight performance results by the clock speeds of the processors, then you can tell whether there is any actual advantage conveyed by the Intel architecture. THEN you can look at price and determine value. When this is done, IMNSHO, the AMD is the hands-down better processor.
I know you kind of conceded this point in the review, briefly, on your way to saying "Oh Boy! Wait till we get the NEW Intel CPUs!!" Just thought you bent over backwards to minimize the P4s downside. (Of course, that's the hazard of doing h/w reviews, huh?)
And you didn't even mention, that, to use a P4 you have to give money to those sleazy Patent Pirates, RAMBUTT!! THAT's a reason not to go Intel, right there....