Dual Processors - Is it worth it?

[klear]

I was just reading www.tomshardware.com 's review over all dual processors. I was under the impression that the dual processors would essentialy mean that if you had 2 1ghz CPU's, you'd have a 2ghz machine. Most software doesn't have the full dual processor accelleration, making your extra heap of money worthless. Another thing is that the performance difference is most of the time significantly less than double, even with the accellerated software.


I guess my question here is, Am I under the wrong impression? and does the Seti client have dual processor accelleration?

 

[Cy]

Klear,

Dual cpus will not give a general doubling of performance. As you have read most sotfware is not designed to take advantage of the extra cpu and even those that are still don't get near a full 2x boost. There is some overhead in operating both cpus so a full 2x is never quite possible. This also applies to high multiples such as 4 cpus and 8 cpus etc, the overhead gets worse as you go up.

What you can get with dual cpus is a boost in performance for some applications and a really big boost in overall mutli-tasking. How much these benefits are worth is up to the individual. I have worked on both types of machines and I really prefer a dual over a single. I would rather have dual 1gs than a single 1.5-2g machine because the multi-tasking is better on the dual and I don't have any tasks that demand pure speed in order to function well for me.

I run dual durons at work and am putting together a dual duron system for home now as well.

To answer you question SETI is not multi-threaded software but you can run two instances of SETI on a dual machine, this is what I do on all my duallies at work and home. For those that like to really crunch SETI it is cheaper to go dual than to build completely separate machines for each cpu.

Please keep in mind that part of running dual prcessors is using an OS that can use the extra processor. Win9x can not do this so you will need to use NT, 2K, XP, Linux or some other unix variation.

HTH

Cy

 

[TC]

Dual cpu's doesn't mean double the power, even if an application is coded to make use of 2 or more. It does however give you two processors in one box, so it's nice if you want to run two instances of seti - you don't need two complete boxes to do so.

 

[LandShark]

just for SETI alone:

duallie crunch slower than 2 single rigs. i suspect it's mainly due to the chipset performance.

my dual XP @ 1.67G (MPX) crunch each WU slower than my single XP @ 1.6G (KT266a)!

the advantage is it save lots of room, i hate seeing all those big white boxes laying all over the place. and when u really using it, u don't notice as much of slow down as a single CPU rig when multi-threading. (crunching SETI while encoding MP3s, burning CDs, etc.)

down side is, except a few high end CAD/Rendering programs (Maya, Lightwave, 3DS MAX, etc.) that really take advantage of both CPUs, there's not much (very little) of performance jump even when using some multi-threading enabled programs. (like Photoshop only gets 'bout 10-15% speed increase).

 

[Beelzebub]

Ya, but with a dual setup you don't have to purchase an extra set of licensed software and peripherals such as video cards, NICs, RAM. Plus, it saves on space if it is at a premium.

You might not get double the performance, but you don't get double the cost either. Sure you need to spend a lot more on the board, but other than that, it is a good alternative to purchasing 2 computers and having licensed programs on 2 computers.

 

[TC]

Ya, but with a dual setup you don't have to purchase an extra set of licensed software and peripherals such as video cards, NICs, RAM. Plus, it saves on space if it is at a premium.

You might not get double the performance, but you don't get double the cost either. Sure you need to spend a lot more on the board, but other than that, it is a good alternative to purchasing 2 computers and having licensed programs on 2 computers.

Very good point I forgot to mention.

 

[AudiMan]

I agree, when I had two XP-1700's in my dual it took about 4 to 4:15 hours for a WU in comparison to about 3:45 in the single setups at the same clock speeds. However it is a lot cheaper than buying two computers.

 

[FRANK]

All of the above replies are true.

Simply put,
With two processors you don't do things twice as fast, but you can do twice as many things as fast.

I'm sorry if this confuses anybody but it makes sense to me.

 

[AudiMan]

Well yeah, it's almost like having two computers. You can use two computers to crunch two separate instances of SETI @home just like in a dual, but you can't use two separate computers to crunch seti in half the time,,, same as a dual.

 

[klear]

Wow, dual makes much more sence to me now.. I didn't know you could run two instances of seti.

Thanks for all the replies guys...

 

[BadThad]

If you use SETI Driver, you can specify 2 processes and each cpu will peg at 100%. I have an old dual PPro rig that does pretty good at seti. Once a week I dump about 10 wu's from it. I love dually setups for SETI.

 

[AudiMan]

Yeah, totally. I wonder when the first dual clawhammers are coming out.

 

[Yomama]

I agree, when I had two XP-1700's in my dual it took about 4 to 4:15 hours for a WU in comparison to about 3:45 in the single setups at the same clock speeds. However it is a lot cheaper than buying two computers.

Is that really 4:15 for a wu? I am thinking that it is 4:15 for 2 WU (only you see just one of them on the display), so eventhough you never finisih any one unit in a very fast time you are completing 2 in a very reasonalble time and it it should result in 4:15 / 2 = 2:08 per WU. Pretty fast

 

[AudiMan]

No, I had two instances of SETI running for the purpose of the SETI network monitor. I'm positive tot he 4 hour WU times because I saw the results in SETI Queue.

 

[TC]

I just setup my first A7M266D box last night. I put a pair of XP 1900+ in it, and bumped the fsb up so they were running 2100+. It's taking about 3.5-4 hours to do average units with two instances of the client running. Definitely a tiny bit slower than a single cpu system of the same speed, but it's not bad. Definitely worth having two cpu's in the same box. One less case, psu, video card, nic, hard drive, ram, etc etc.

 

[Basher]

Is that really 4:15 for a wu? I am thinking that it is 4:15 for 2 WU (only you see just one of them on the display), so eventhough you never finisih any one unit in a very fast time you are completing 2 in a very reasonalble time and it it should result in 4:15 / 2 = 2:08 per WU. Pretty fast

Well that is the total time for 1 WU, just remember that there is also another one running at the same time on the other cpu so in 4 hrs it will complete 2 wu's each taking 4 hours.

 

[LandShark]

I just setup my first A7M266D box last night. I put a pair of XP 1900+ in it, and bumped the fsb up so they were running 2100+. It's taking about 3.5-4 hours to do average units with two instances of the client running. Definitely a tiny bit slower than a single cpu system of the same speed, but it's not bad. Definitely worth having two cpu's in the same box. One less case, psu, video card, nic, hard drive, ram, etc etc.

sounds it running fine. glad to hear that TC.

since u r having version 1.03, so both CPUs r running at stock volt.?? what kinda FSB and memory r u using??

 

[TC]

sounds it running fine. glad to hear that TC.

since u r having version 1.03, so both CPUs r running at stock volt.?? what kinda FSB and memory r u using??

Yep it's 1.03, but I decided to keep it anyway. I put in a 256 stick of corsair pc2400 and bumped it up to 144, so it's just a couple MHz below official 2100+ rating. It's been running seti for a little over 24 hours with zero problems, so I feel pretty confident it's solid. This is even with the retail box heatsinks and the thermal goo they come with. I'm pretty happy - put it together in under an hour and had absolutely zero problems from start to running windows. And of course somebody else will buy one because of this and have a completely different experience, right

 

[LandShark]

what kinda power supply r u using?

wow! stock heatsink? never tried, but i really wish i have 2 stock heatsink to test it.... the Millneium Glaicator is pretty quiet, but add 2 together still a bit noisy for me tho....

that's the same memory i'm using too. but have 2 stick of 256 in it.

crunch on!!

 

[TC]

what kinda power supply r u using?

wow! stock heatsink? never tried, but i really wish i have 2 stock heatsink to test it.... the Millneium Glaicator is pretty quiet, but add 2 together still a bit noisy for me tho....

that's the same memory i'm using too. but have 2 stick of 256 in it.

crunch on!!

You're gonna hate me now - squeakin by with an enermax 350. I used the retail heatsinks because I figured I wouldn't try to overclock with the 1.03 mobo, but that didn't last long after booting it up. Overclocking is just in the blood