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Comment: Re:nvidia/ATI should keep their new stuff propriet (Score 1) 309

by m.dillon (#49481879) Attached to: NVIDIA's New GPUs Are Very Open-Source Unfriendly

I don't understand what you mean by 'non graphics competitors'. Intel, AMD, and ARM cpu offerings already have integrated GPUs with dual-head capability (and have for a few years now). There are no non graphics competitors.

Currently the best open source kernel and driver compatibility is with the Intel and AMD integrated GPUs. That's what all the KMS work was responsible for giving us. The performance of integrated GPUs has increased steadily over the last few years and has reached a point now where most 3D games will run with modest (but not high-end) settings, and *all* 2D (aka desktop operations) will run faster than you can blink.

I splurged for a mid-range card for my windows gaming box, but all my workstations just use the cpu-integrated gpus these days for dual-head operation. And they're nice and quiet and fast.

-Matt

Comment: Consumers are not going to notice much difference. (Score 2) 72

by m.dillon (#49479447) Attached to: Samsung SSD On a Tiny M.2 Stick Is Capable of Read Speeds Over 2GB/sec

Well, nobody with a laptop is really going to notice much of a difference because frankly there isn't a whole lot of software that actually needs that kind of performance over the ~550 MBytes/sec that can already be obtained with SATA-III. Certainly not that would be run on a laptop anyway.

It's just using the PCI-e lanes on the M.2 connector instead of the SATA-III lanes. This isn't a magical technology. There's a loss of robustness and portability that gets traded off. It does point to SATA needing another few speed bumps, though. The fundamental serial link technology used at the physical level by PCI-e and SATA is almost identical. The main difference is that SATA is designed for cabling while M.2 is not (at least not M.2's PCI-e lanes).

-Matt

Comment: Re:Should be micro kernel (Score 5, Interesting) 207

by m.dillon (#49467613) Attached to: Linux Getting Extensive x86 Assembly Code Refresh

Nobody does message passing for basic operations. I actually tried to asynchronize DragonFly's system calls once but it was a disaster. Too much overhead.

On a modern Intel cpu a system call runs around 60nS. If you add a message-passing layer with an optimized path to avoid thread switching that will increase to around 200-300ns. If you actually have to switch threads it increases to around 1.2uS. If you actually have to switch threads AND save/restore the FPU state now you are talking about ~2-3uS. If you have to message pass across cpus then the IPI overhead can be significant... several microseconds just for that, plus cache mastership changes.

And all of those times assume shared memory for the message contents. They're strictly the switch and management overhead.

So, basically, no operating system that is intended to run efficiently can use message-passing for basic operations. Message-passing can only be used in two situations:

(1) When you have to switch threads anyway. That is, if two processes or two threads are messaging each other. Another good example is when you schedule an interrupt thread but cannot immediately switch to it (preempt current thread). If the current thread cannot be preempted then the interrupt thread can be scheduled normally without imposing too much overhead vs the alternative.

(2) When the operation can be batched. In DragonFly we successfully use message-passing for network packets and attain very significant cpu localization benefits from it. It works because packets are batched on fast interfaces anyway. By retaining the batching all the way through the protocol stack we can effectively use message passing and spread the overhead across many packets. The improvement we get from cpu localization, particularly not having to acquire or release locks in the protocol paths, then trumps the messaging overhead.

#2 also works well for data processing pipelines.

-Matt

Comment: Re:Can we be sure there are no exploits? (Score 2) 207

by m.dillon (#49467579) Attached to: Linux Getting Extensive x86 Assembly Code Refresh

Well... basic procedures using only MOV/CMP/JMP is not something that even linux really needs to code in assembly. What is being talked about here is primarily the trap, exception, syscall, signal trampoline, and interrupt entry and exit mechanisms. Also thread switch code can get pretty complex because there is a lot more hardware state involved than just the basic register set. When you start having to deal with SWAPGS and MSR registers, you've really gone down the rabbit hole.

-Matt

Comment: It's only a modest refresh (Score 4, Insightful) 207

by m.dillon (#49467535) Attached to: Linux Getting Extensive x86 Assembly Code Refresh

It's not a major refresh, only a modest one, and it doesn't really fix the readability issues (which would require a complete rewrite). Linux assembly is a mostly unreadable, badly formatted, macro-happy mess. The assembly in the BSDs is much more elegant and minimalistic.

-Matt

Comment: The core of the issue (Score 2) 278

by m.dillon (#49451523) Attached to: The Myth of Going Off the Power Grid

The core of the issue has nothing to do with going off-grid and everything to do with matching production from renewal sources to the actual load on the grid. Without that we get into the situation that Germany finds itself in, which is two fold: (1) That electricity prices fall to zero during the day due to all the solar, and as subsidies go away the owners can't make money from providing power to the grid. And (2) The base load differential between day and night is so great that the traditional generation (i.e. coal) cannot run continuously at critical mass and so becomes extremely inefficient and uneconomical. So coal power generation companies in Germany are also going bankrupt.

Ultimately consumers with PV systems will be forced to pay spot rates and feel the pain. This is already beginning to happen in many parts of the country... where day-time electricity rates are lower but the buy-back is also lower, and night-time rates are higher and have a higher buy-back.

The idea with using the electric car battery (or some other form of temporary storage) is to use it store energy when prices are cheap and inject it into the grid when prices are expensive. This also has the side effect of reducing the base load differential between day and night, so other generation sources such as nuclear and coal can operate efficiently (and thus profitably) to make up the difference.

There is nothing nefarious going on. Really, going entirely off-grid is not something anyone should be trying to do unless they actually live somewhere with a flaky grid (or no grid). And the reality is that electricity prices are going to fluctuate even more between day and night, or rainy vs not, or windy vs not, as more renewable energy sources are brought online.

-Matt

Comment: Re:Time to stop considering individual components. (Score 1) 85

by m.dillon (#49448099) Attached to: Intel's Core M Performance Is Erratic Between Devices

Depends on a lot of things but one thing for certain... swap on a SSD greatly improves system responsiveness when you have a lot of open applications (on any OS: Windows, Mac, Linux, BSD). Being able to page out anonymous memory to fast swap is a big deal. Nominal file storage on a SSD greatly improves program startup, boot times, photo and document handling. I've found though that it's really having swap space on the SSD that makes the biggest difference. I have a multitude of machines ranging from 1GB to 32GB of ram, with various cpus.

My 2GB haswell-based chomebook is snappy for the tasks I use it for (of course, I replaced the 16G SSD with a 128G SSD and run DragonFly on it). Heck, I even still have an old pre-haswell netbook and throwing a SSD into that made it usable again (but these days I only use it for legacy testing). But I'm really happy with Intel's haswell-or-later based laptop cpus.

There are some caveats. Firefox has huge gaping memory leaks and horrible memory footprint use, so leaving it open in the background for a few days usually builds it up to around ~2GB VSZ and 1.5GB RSS (and it keeps growing. On my 8GB workstation I've let it grow well past 4GB before closing out all the windows and reopening it). If it just paged all that leaked memory out it wouldn't be a problem, but it's so fragmented internally that it winds up touching most of the footprint under normal operation all the time. In this situation, having a bit more memory on the workstation or laptop does help quite a bit.

Another caveat is of course any heavy cpu workloads, such as batch photo or video processing or large compiles. But nobody in their right mind runs that kind of workload on a laptop anyway so.... maybe not so much of an issue.

Other than the browser, there isn't really a whole lot that eats memory to the point where you'd notice it. And beyond photo/video processing, only large compiles really loads down these modern cpus enough to be noticeable.

-Matt

Comment: Opcodes still burned in my brain (Score 4, Interesting) 140

by m.dillon (#49398975) Attached to: Building an NES Emulator

I started serious programming (at around age 14) on the Pet. First in BASIC, but once I found out you could break into a machine language monitor by wiring up a NMI button (we called it the two-button salute), there began my machine coding. In HEX, directly. Didn't even have a relocator at the beginning. It was a year before I could buy the expansion rom to add disassembly and relocation features to the machine language monitor.

Ultimately I wrote an assmbler too. I don't think I have any of that code any more, it's been lost in time. Kinda makes me sad.

The PETs 8-bit IEEE-488 bus was pretty awesome. The PET had a 1 MHz 6502. The external floppy drive also had a 1 MHz 6502 in it, and you could reprogram it. So one of my many projects was to speed up the data transfer between the two by synchronizing the processors with a series of handshakes and then pushing or pulling the sector data without any further handshakes (using processor timing).

My friend did the same thing for the C64's serial interface (which didn't even have a uart) and sold a product called '1514 Flash!' that sped up the serial interface. Basically a little messing around at the beginning of each transfer to get the two sides synchronized within 1 clock cycle of each other and then pushing/pulling bits as fast as the little cpus would go without any further handshaking. The clocks would stay synchronized long enough to copy a whole sector.

Other projects on the PET... it had a character generator rom which I replaced with a static ram. so when I powered it up I had to load a copy of the original rom into the ram blindly (because the display was total garbage due to it being an uninitialized ram).

The PET had built-in CRT screen but the key was that the data input for the screen was actually a TTL input! So I could pop the wire off the connector and use it like a digital oscilloscope to probe various TTL-based projects (as well as the PET's motherboard itself).

Another project...the character generator rom had something called quarter-block graphics. Basically 16 characters that had all 16 combinations of four quarter-blocks (2x2), so you could (I think) 320x200 graphics on it. I spent many hours optimizing the machine code to generate a pixel pusher.

I got so good at writing editors from scratch, once when I went to computer camp and forgot to bring the tape I rewrote the text editor in machine code in less than an hour.

Met Richard Garriott at that camp too, we were both on staff. He was working on (I think) Ultima II at the time (on an Apple II I think) and had an awesome ram disk for storing code temporarily while he was working on it. Once his computer stopped responding and after unsuccessfully trying to resurrect it he finally gave up and power cycled it, losing his work in the ram disk. It turned out he had accidentally disconnected the keyboard and the computer was actually fine. Oh well! Richard taught a class at that camp on human-interface parsing... basically had people write a dungeon game where you typed in what you wanted to do in English. Primitive of course, but the kids had a blast.

I wrote a centipede game in machine code, incredibly fast and awesome (the last level the centipede was invisible and only blinked into existence for a second or two every few seconds), and submitted it to Cursor magazine. They rejected it because they thought I had stolen it from someone :-(. The only thing I ever tried to get published, rejected because the code was *too* good!

The 6502 had two awesome indirect EA modes. (TABLE,X) and (ADDR),Y, along with the standard modes.

Decimal mode wasn't as interesting, I wound up not using it for display conversion at all.

The 6522 I/O chip was an incredibly powerful chip for its time, with multiple timers and timer-driven events. It had a few bugs, too.

I remember all the unsupported machine codes the 6502 had. It was a hardwired cpu so all instruction codes did *something* (even if it was mostly to just crash the cpu). LDAX was my favorite. Mostly, though, the hidden codes were not very useful.

The list goes on. Twas an awesome time, a time before PCs took over the world.

-Matt

Comment: Re:Advert for Razer? (Score 1) 199

by m.dillon (#49347505) Attached to: What Makes the Perfect Gaming Mouse?

Not sure what that guy was complaining about but I love my Razer Blackwidow ultimate (2013) keyboard. I grew up on heavy n-key-rollover IBM keyboards and then had to make due with horrible light, cheap, keyboards for many years until I found the Razer. It's worth the price for me. And I've gone through probably 30 or 40 keyboards over the last 35 years.

* Heavy, it doesn't move around.

* USB extension port on the right hand side is perfect for my wireless mouse's transceiver plug.

* N-key rollover that actually works, solid tactile (mechanical) response. I can type at 80+ WPM again.

* And doesn't have thousands of useless extra buttons.

Since a Razer engineer is listening. My suggestions:

* Have a usb port on the left side as well as the right side.
* Change the middle-bottom symbol. I don't quite remember... it might have been backlit before and I took the keyboard apart to disconnect it. It was a distraction.
* Don't reverse the upper and lower-case symbols on the keycaps. That was kinda silly.
* The bottom feet could be a little more robust.

In terms of mice, I use a simple microsoft or logitech wireless mouse now. Simple three button w/wheel... I don't like extra buttons or left/right buttons and when I play games I tend to map most features to the left-hand side of the keyboard rather than to a complex mouse. That way I can bang the mouse around without accidental button pushes. I prefer wired mice but for the last few years I couldn't find any at the stores I frequent.

The wireless mice are fine as long as (A) the tranceiver is within a few inches of the mouse, which it is hanging off the keyboard's RHS usb port. and (B) You use a AA alkaline (non rechargeable) battery. Rechargeable batteries just don't last due to charge leakage. And of course keep a spare battery within reach or replace every month whether or not it needs replacing.

-Matt

Comment: That will be amusing (Score 1) 262

by m.dillon (#49339395) Attached to: RadioShack Puts Customer Data Up For Sale In Bankruptcy Auction

Whenever Radio Shack asked me for my address I just said I wasn't interested in giving it to them. But a friend of mine did one better... he always wrote down the address of the White house and signed it Mickey Mouse. And the sales person dutifully entered it into the computer, no questions asked.

-Matt

Comment: Re:At What Frequency? (Score 3, Informative) 83

That is not a correct description. Lower frequency radio waves are no less 'quantum' or 'classical' than higher frequency radio waves. AM radios can penetrate objects primarily because they have a wavelength on the order of 400 meters (up to around 1 MHz), whereas FM radios have a wavelength of only a few meters (through around 100 MHz). The longer wavelength of AM effectively allows the radio wave to bypass even relatively large objects such as mountains.

The same effect can be seen even within your house if you have a dual-band WIFI router. The 2.4 GHz band is able to penetrate walls and go around corners and reach the second floor far more easily than the 5 GHz band can.

-Matt

Comment: What morons (Score 1) 486

by m.dillon (#49336901) Attached to: No, It's Not Always Quicker To Do Things In Memory

What morons. Sorry, but they are. They are writing to a file through the operating system which means that it is being spooled out to disk asynchronously, so obviously piecemeal writes are going to be faster because they will run concurrently with the string generation algorithm. Plus their 'writes' are probably being buffered in ram anyway.

Writes to files generally do not stall programs. These people are morons.

-Matt

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