Yes,some SPUs have multi-processor interfase support.
Some kinds of those boards for differen CPU types (P-III, Alpha, Athlon ...)are existing and available for sale...

But WHAT do you want to ASK ? :)

I'm going to use a PC for a music application (Emagic Logic Audio) which uses a lot of processor power.

If I had a PIII 800Mhz processor, and added a 500Hhz processor, would this then work as if it had 1300Mhz processing power?

No it would not work.  First off, they have to be the same CPU.  Next, it has to be an operating system capable of using the multiple processors.You would need NT/2000 to make use of a second, third, etc processor or your program would have to be designed to use the additional processor(s) as the article below states.
Windows 95/98 Does Not Use Multiple Processors

--------------------------------------------------------------------------------
The information in this article applies to:

Microsoft Windows 98
Microsoft Windows 95
Microsoft Windows 98 Second Edition

--------------------------------------------------------------------------------


SUMMARY
Neither Windows 98 nor Windows 95 uses more than one processor on multiple-processor computers.



MORE INFORMATION
Windows is designed to use a single Intel-based processor. If you install Windows on a computer with more than one Intel-based processor, Windows uses only one of the processors and ignores the rest.

If you need an operating system that supports symmetric multiprocessing (SMP), you may want to use Microsoft Windows NT instead of Windows 98 or Windows 95.

Note that some third-party programs may make use of a second processor under Windows in a programmatic manner (most notably, computer-aided design [CAD] programs). The use of a secondary processor is dependent upon such a program and is usable only by that program.

 

No.  It's not that simple, and problems with the speed at which the processor accesses the system bus and memory would prevent a configuration like that working.

You should place processors in a board like this in identical pairs (or 4's or 8's, etc -such computers do exist).  Providing your operating system supports SMP (symmetric multi processing) you will see a noticable speed increase.  Basically what is happening in this case is the operating system hands off chunks of the processing (threads) to whichever processor is available, thus spreading the load.  You won't exactly see a doubling in performance though as there is an overhead involved in deciding which process goes where.

That was a simplified explanation.

Actually checking the system requirements for emagic logic audio platinum, shows that the minimum spec is a P200 with 64Mb of RAM.  Therefore if you had a machine with a P3 800, and lots of ram (256 MB) you'd be more than alright.  In a lot of cases it's the amount of memory that makes the difference over raw processor speed.

OK, so if it were 2 of the same CPU's running on Windows2000 would it double the processor speed?

Can you tell me the name of one of these boards so I can look it up.

Thanks

Thanks izwiz, I posted my last comment before I received your reply.

Here is a nice list of multiprocessor motherboards.
http://www.pcbenchmarks.com/reviews/Motherboards/Multiprocessor/

Thanks izwiz, I posted my last comment before I received your reply.

OK, I'm trying to find out if Logic runs under Windows 2000. Are the multi-processor boards as good as the regular motherboards?

Here is a document which gives you instructions on getting Win2k up to multiprocessor support.
http://support.microsoft.com/support/kb/articles/Q234/5/58.ASP?LN=EN-US&SD=gn&FR=0
Whenever you decide if your software will run on Win2k and get it installed, this article should help on getting support for all processors.

OK, I'm trying to find out if Logic runs under Windows 2000. Are the multi-processor boards as good as the regular motherboards?

I'm running win2k on a supermicro PIIIDME motherboard with 2 PIII 667 and it is FAST!!!

OK, I'm trying to find out if Logic runs under Windows 2000. Are the multi-processor boards as good as the regular motherboards?

Yes, multiprocessor boards are as good as single boards.  It stands to reason really, the boards are designed for either high spec workstation or server machines, so they need to be well specified and reliable.

One point with dual processor systems is that often they work better if the processors are a matched pair, that is they are from the same batch. Sometimes two processors that are apparently the same, but have different minor revision numbers might have really small timing differences that can upset some dual CPU boards. So if you buy a board that takes 2 CPUs but is capable of running with one, and you just want to get one initially, try and find a place that will let you trade in your first CPU against a pair later.

Thanks for that point RoagWarrior

IMHO the best multiprocessor boards are made by Supermicro, which specializes in them.  I own two of their multi boards, each with two procs in it.  One of them has a P2 fabbed in Malaysia and the other P2 is from Indonesia so as for claims about needing to be in the same batch, well, either I got really really lucky or Supermicro's board works with anything.

Here is their site:

http://www.supermicro.com/

Click 'Products' and then pick a chipset to see motherboards.  They make a quad Xeon but it's out of any home user's budget.

As for speed, well, I use linux on one and it is a LOT faster when the second CPU is added for just about all programs.  The other uses NT and it is not quite so dramatically faster but there is a boost for a second CPU with it.  Mainly because with linux you can recompile your programs for your system whereas with NT you have to find a multiprocessor aware version of your software.  But even if you can't find those versions NT will do system functions on one CPU while the other one runs your program.

regards,
magarity

You have got enaugh proper answers already, generally multiprocessor motherboards can accelerate your computer 30 to 60%, but as it was stated before, You must use OS or application which support multiprocessing, but the other hardware components should be able to support processors demands otherwise You'll get a "bottleneck" on the system and the processors power will be swalowed by the wait state. As I understood Your application is dedicated for music processing and needs very precise timing, considering interrupt mode based PC platforms, better solution for Your problem would be one of hardware music processors which can be mounted on Your modherboard.


Hope You already have decided what to do

reagrds

lekan

it also must be noted that using dual proccesors doesnt effectivly double your proccessing speed.

however

it does increase the amount of processor instructions that can be executed at the one time. therefore dual processors are generally used to enable and enhance multitasking on nt, or windows 2000 machines

:-)
jazz

ALSO note that software must be _specifically_ written for multiple processors to use them (The applications must multithread) But an app with badly written multithreading will get next to no use of multiple CPU's

I tried a commercial CAD package which supposedly multithreads, however, it used 90% of CPU0 but only 11% of CPU1

Whereas a filter operation in photoshop used 95% of both cpu's

But like someone mentioned above, NT (and most other OS's) will shunt a heavy process which isn't multithreaded onto one processor, whilst running system resources on the other.

Problem is that it will then quite often move the affinity of the process between the objects, causing a lot of context switching. Only way to prevent that is to set the affinity for a process manually.

The biggest mistake made in multi=processor systems is to use different processors, ensure you use the same speed processor WITH THE SAME CACHE, the more cache you can afford on board the better with dual processing, Compaq and many main manufacturers do Professional Workstations that are dual processor ready or sold with both processors.  If you really think you need this speed consider using Xeon processors who have much larger on-board cache and are faster.  With regards to performance you will see (very roughly) a 50% increase in speed over a single processor of the same type.

Yes lots of cache is good because the memory subsystem is strained more by having 2 CPUs , it's like putting half speed RAM in a single CPU system.

Comment accepted as answer