Pentium III review 31
Dennis "Thresh" Fong
wrote in about a
review of the as-yet unreleased Pentium III.
As we know, the Pentium III (Katmai) introduces 71 Katmai
New Instructions (KNI): floating point SIMD instructions.
While 3D-Now! and MMX cannot be used simultaneously to x87
FPU instructions, requiring the use of a state change instruction,
apparently KNI will avoid this performance penalty by using
a new processor mode. If you remember MMX was made multitasking
independent (no specific MMX state to save/restore when switching
between processes) by piggy-backing onto the FP-registers whose
state is saved by all x86 multitasking OS's. Since the new
mode is only activated if the OS knows about it, this is a
safe way for Intel to improve performance.
Hemos:This is strange-I posted this before, but it seems to have vanished-can't figure out why. We're looking into it.
Ignore it, AMD! (Score:1)
Thresh reads Slashdot? (Score:1)
What gives? (Score:1)
P3 VS K7 (Score:1)
It seems likely to me that Intel will only catch up with the K7 when they bring out Merced, but I wouldn't even bet on that! (yup - it would not surprise me at all if the top end K7s that are being produced when the Merced comes out will be faster than the Merced)
Uhhh... (Score:1)
But I do think you're right that for most uses other than games you don't need anything this powerful.
How does MMX et al help us? (Score:1)
Should not these instructions and capabilities sit outside the CPU in ancillary chips (video/what else)?
How does this help in OS speed and capability? Is it that we can perform FP ops better amongst process context switches? I'm assuming graphical subsystems outside the OS.
Leave my CPU alone!! (Score:1)
Celeron 550?? (Score:1)
You've got the CPU - what to do with it (Score:1)
Too many people seem to be looking at this from precisely the wrong angle. They're saying 'normal software doesn't use that much CPU, games can get the performance more easily from 3d cards, ergo we don't need P3/500 systems'.
They're right.
On the other hand, Intel has produced these chips. There will be people around who've *GOT* P3/500 systems. These are chips which can run KDE or similar with 10% of their power; you could run software-rendered Quake 2 as the WALLPAPER, and the user won't notice except that his wallpaper freezes up when he recalculates something big. What do *you* plan to do with them?
At the moment, my machine is 80% idle at most times; if you looked only at instruction traces from the CPU, you'd guess I was a special-purpose device for checking Mersenne numbers for primality. Some of you would see the same result; some would be told they were running HLT instructions 90% of the time, some would be told they're using 20% of the cycles on a box which is basically doing RC5 trial encryptions.
But Mersenne numbers, RC5 trial encryptions, and much more so HLT loops, are not directly useful to the man whose box is providing the cycles. Quake 2 wallpaper would be nice to watch, but not what I'd call useful. Speech recognition might need fair numbers of cycles, but again it'll usually need them while the user is speaking rather than all the time.
It's embarrassing to have to ask the question 'what useful things can we do non-interactively with a dedicated P2/400', but we've got to that point now.
Leave my CPU alone!! (Score:1)
You want things on the CPU die.
Really, you do.
Why? Because, on the CPU die, a 128-bit 400MHz bus is ten lines of VHDL. It's 0.06 millimetres wide. You can have dozens of them lying around. Off the CPU die, it's 128 IO pins - and the CPU's only got space for 600 or so such - and 128 PCB traces which have to be at least 0.5mm apart; it's a *big* orange ribbon on your motherboard.
What you have at the moment between your CPU and your graphics card is a 66MHz 64-bit bus. If the graphics card was on the special-purpose PCB inside the P3/500, you'd have a 250MHz 64-bit bus. If it were on the CPU die, you could have as many 500MHz 128-bit busses as you pleased.
I *want* integration. OK, I can't upgrade the graphics and the CPU separately - but you don't do that often anyway. You have big upgrades where you yank the motherboard and most of the cards, and replace the whole pile. Why not just replace the CPU?
Yes, Intel might not have the in-house expertise in gfx chip design - but nvidia would cost them less than $10^9, and that's a sum any bank would be pleased to lend them tomorrow.
*Everything* belongs in the CPU MCM. Seymour Cray knew that in 1986.
Ignore it, AMD! (Score:1)
I'll be amazed if the successor to the K7 (the K7's already taped out) doesn't deal with KNI; AMD isn't quite yet in a position to become incompatible with the way Intel's steering IA32. It's OK if some AMD stuff doesn't run on Intel; if any Intel stuff doesn't run on AMD then AMD gets horrendously bad publicity.
Remember, AMD get to implement it after seeing how Intel did it; they can stick in four KNI pipelines where Intel had only one. Just for that reason I'd expect them always to be ahead of Intel's last major revision.
The Name Game (Score:1)
Pentium
Pentium Pro
Pentium MMX
Pentium II
Pentium III
weird (Score:1)
what the fsck (Score:1)
Overclocking... (Score:1)
Note that I do see the reason those brain-dead Celerons are overclocked, as you seem to be able to get it to run 50 percent faster. But do people really notice less than 10 or 15 percent?
Here is the disappearing story from Saturday (Score:1)
That's the other one that got yanked after attracting around 100 comments.
84.6 !!! (Score:1)
granted that's without a fan but damn! something just isn't right when i can cook my jiffy pop over my processor.
I know (Score:1)
Just pretend this is your first time reading this, and nobody gets hurt
Intel Can Suck It (Score:1)
The alternative to this was RISC a processor design that lets you process several instructions per cycle. This is what Mac's use, and of course, Macs do suck, but thats because of the OS. You stick Linux on any mac, and watch it fly. Not to metention that Mac's make good crackers, for things such as DES and RC5.
At some point, Intel will figure out that CISC is old, and its out of its league, switch to RISC, and act like they created the damn thing.
Another bad thing about the Pentium III is that is Un-Overclockable. One of the nice things about the older processors is with a few jumper settings, you could get PII's to run as high as 504mhz! And this is from a PII 333/300!