Spice Accelerator Hardware?

Dear Friends, I'm very new in using Spice. Is there any accelerator hardware that speeds up the simulation of circuits?

Best Regards!

Reply to
Douglas Mota
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Many years ago, Inmos speeded up their SPICE simulations (they were using a VAX) by porting SPICE to a transputer array.

You might be able to use a high-end graphics card as an accelerator. It would be a lot of work, though.

Leon

Reply to
Leon

These people claim they've licked the partitioning of a Spice Simulation up into multiple processors running multiple copies of your own Spice Simulators. They claim a nearly linear increase in speed by adding more processors.

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Wouldn't know.

Robert

Reply to
Robert
[snip]

You are correct.

P3 -> P4 = Slower PSpice by more than 1/2

AMD is now roughly 8-9X faster than an equivalent speed P4, when running PSpice.

Also an observation, don't know if it's real or happenstance, Win2K is MUCH more stable on my AMD machine than on my P4 machine.

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

[snip]

Yep. Back in the early x86 days you had to buy a separate math co-processor chip.

Intel apparently has decided their mass market is the gaming/graphics crowd.

Heaven help us home-brew engineers if AMD turns that direction :-(

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

Chances are you are best off with:

Buy a very fast PC with a large amount of RAM. Ideally it should have the

64 bit CPU.

Install SuSE 10 for 64 bit, wine and LTSpice.

I've run LTSpice on 4 OSes and it appears that the speed is:

Win-XP Slowest \\ Call it a tie because I'm not Win-98 Slowest / sure which was faster Suse-9.2 32 bit Suse-9.3 64 bit Fastest

If you are using XP make sure that the spice is not running in "98 compatible mode". That mode slows things down a lot. There are a bunch of other things you can do to speed things up under XP. Tell your IT guy what you need. He should be able to speed things up a bit (given perhaps a week).

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kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

And then there's always the Intel vs. AMD difference. They benchmarked PSpice back where I worked a number of years ago and found a significant speedup with the AMD CPU. But that was quite a while ago. Don't know if it holds nowadays.

Robert

Reply to
Robert

I'd assume PSpice uses a lot of floating point calculations. Intel's always favored Integer and general CPU operations over floating point given their target markets so their floating point performance always sucked compared to the competition.

And it's gotten worse with the P3 -> P4 transition. Relatively speaking.

Then again, they fell down when AMD brought the Memory controller on-chip for increased performance. Intel seemed to not develop the x86 architecture in favor of their Itanium, i860, and other attempts.

Robert

Reply to
Robert

Huh? The Gaming/Graphics crowd likes a lot of the stuff the Engineering crowd does. Though the Hardware tends to be dedicated.

Intel seems to have decided that the Business crowd was the main Market. General Word Processing, limited Spreadsheets, Power Point, Email and such. Then the other major market being the home user with some of the above.

Given the Markets the way they have been I can't say they were/are wrong. Engineering and other math intensive stuff has always been a minority part of the Markets. The major math intensive stuff, graphics, moved off into dedicated cards long ago that today rival the CPU for number of transistors. Similarly for Audio.

Intel has always had ambitions to move that function into the CPU, or at least the Chip Sets they make. And the hardware's gotten powerful enough to do that with the low up to medium end. Maybe that trend will continue with the newer multiple processor cores.

Robert

Reply to
Robert

A few years ago, I made benchmarking for Intel (Windows), Sparc (Solaris) and PowerPC (Mac OS X) with Lapack (solution of a system of linear equations). It happened that Intel needed a doubled processor clock to reach the same performance, that is, 800 MHz Intel was about the same as 400 MHz Sparc or PowerPC.

I guess, the reason was a smaller L2 cache on Intel processors and, as such, much less efficient BLAS. The processor clock is not everything.

I highly recommend you to browse BLAS (especially BLAS level 3):

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Without tuned BLAS libraries, you cannot have a good performance in linear algebra applications.

Best wishes,

Evgenii

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Reply to
Evgenii Rudnyi

You are joking right? Until K7 there was only intel in that space. I'm not an intel fanatic but come on.

XTC

Reply to
Andrzej XTC

The few serious gaming folks I knew (2 years ago) went for the AMD processors. AMD has been the favorite by the high-end gamers back a few years. BTW Jim, I only see a 2:1 difference per GHz in AMD vs. P4 with things like PSpice. The newer P4 processors are a bit more efficient than the old P4s, but not really significant. AMD 64-bit processors have much better memory management than the old AMD 32-bit and Intel processors. The AMD 64-bit processors under Win 2k have the same processing efficiency as the old 32-bit units, but much better memory interface. Unfortunately, PSpice doesn't seem to be affected much by memory performance. FPGA floor planners are given a major boost by AMD's 64-bit memory controller scheme over the old AMD 32-bit processors. The old AMD 32-bit CPUs have an abysmal memory controller scheme by any standard!

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Mark
Reply to
qrk

Hi Leon, Your idea of using a graphics card seems to be interesting. Maybe it could be a nice theme for a graduating project or even a PhD thesis... Thanks a lot!

Reply to
Douglas Mota

I'm a bit surprised about your results with WinE/SuSE, since WinE is an emulator that adds a processing layer, when compared to the Windows experiment. "Even in my wildest dreams" I could think that WinE would be faster than WinXP itself ! Thanks for your suggestion, it will certainly help to guide me when I upgrade my PC. Regards!

Reply to
Douglas Mota

This is only true if it's a 16 bit program, which -- even though Cadence has not been particularly kind to PSpice in the past few years -- I can't imagine PSpice is. It's a fair bet that any software written in the fast 3-5 years is a native 32 bit application.

This is pure nonsense; DOS itself was written in assembly language.

That has nothing whatsoever do so with the core Windows vs. SuSE OSes, it has to do with how the 'desktops' go out and list the network neighborhood. XP tries to be 'smart' and queries each machines as it sees it to retrieve additional information about what resources it has, and this can be noticeably slow. OK, I suppose this is still 'part of Windows XP,' and I'd be the first to grant you that plenty of the included bits of XP are pretty lame, but then again, so are plenty of the included bits of any *NIX OS as well. At their cores, XP and *NIX are both decent OSes, and XP is arguably more sophisticated (hence part of the reason Microsoft's IIS has better performance than Apache on *NIX, Plug-N-Play -- while certainly not 100% trouble free -- tends to work better than on *NIX, etc.)

---Joel Kolstad

Reply to
Joel Kolstad

Go take a look at the wine site. Wine stands for (W)ine (I)s (N)ot (E)mulator.

Wine is an implementation of the windows API under linux. This means that it is code that does the same functions for the same calls as windows does but it doesn't use Microsoft(tm) code to do it.

When you run a program under XP, the body of the code runs in the 8086. When it comes to a windows API call, XP has to switch to 16 bit mode to call the WinME code, the WinME code then calls the Win98 code, which calls the DOS-6.0 code, which was written in MS-Basic. This is why XP is so slow. :>

BTW: At work I showed an XP user that my "network neighborhood" still worked ok now that there are XP machines on the network. He was stunned at how fast the display came up. I thought my SuSE was going a little slow. At least on this one function SuSE seems to be much faster.

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kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

Oops. Sorry. :-) Some people really do thing that 'everything is still built on top of DOS' in XP though!

Reply to
Joel Kolstad

Try engaging your sense of humor and re-reading what I wrote above.

[...]

I don't think that this is right. When the SMB "master browser" was acting up, the XP machines couldn't see the same things as the Linux ones. I think XP still uses the NMB as its source of information. At least thats how it appears.

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kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

Yes the ignorance in amazing. Everyone knows it is all built on top of MS-Basic.

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kensmith@rahul.net   forging knowledge
Reply to
Ken Smith

Hi Ken, Do you know why has LTSpice run faster over a 64 bit OS, even though it's a 32 bit application? Sorry if it's a stupid question... Regards!

Reply to
Douglas Mota

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