Single vs. dual processors?
 

I'm still trying to figure out why my system is acting weird. So, while I wait for HW diagnostics and CPU stability tests to run, I'm also looking at NEW systems!! If my current computer acts up one more time (if I ever get it back up and running - I'm using my laptop at the moment), I'm buying a new system.

So, I've been trying to figure out if I want to buy a dual processor system or not. I don't really have the funds to get two really fast processors, so I'm trying to figure out if having, say, two 1.6 GHz Athlons would be better than one 2.6-2.8 Ghz P4.

One thing I've realized is that GoBack doesn't work with multi-processor systems, and I've really come to rely on that application quite a bit over the last few months! So, I'm not too keen on giving that up.

I'm planning on getting a custom-built system, b/c I don't really need new disks or CD-RW drive. So, I'm hoping to get a barebones case/motherboard/powersuppy/CPU that work together - and I'll fill in the rest. I really want to be able to upgrade parts/pieces as the need arises, but I realize that at some point that just doesn't work. (I seem to have reached that point in my current system.)

Any thoughts/experience appreciated.

Thanks,
Jeanie

Jeanie, Multiple processor systems are really designed for file servers. If a program isn't specifically designed to run with a multiple processor it wont be able to utilize both processors. And like Goback some programs may not work very well. I haven't worked with any multiple processors systems that weren't Novell file servers so I don't have a lot of input on what works and what doesn't. If you were running Linux it would be just the thing.

If you plan on using your older hard drive and CDROM then should consider that your hard drive will be your limiting factor as far as speed is concerned. I don't know which hard drive you currently have but only the newest IDE drives from Western Digital and IBM have enough speed to compliment the fastest processors available now.

I just upgraded my PC to an AMD Athlon XP 2100 processor with 1 Gig of ram. My system is waiting on my hard drive at times and I feel that if I was to buy a newer IBM drive I could improve my speed. I have a pair of IBM Deskstar 75GXP 60 Gig drives. The newest IBM 120GXP 120 Gig drives are more than twice the data transfer rate as mine even though they have the same spindle speed and seek rating.

Another thing to consider is the thermal rating of the system you are planning to build. The AMD Athlon chips run hotter than the comparable Intel processors. Both of these processors do run much hotter that what you currently have. I bought a new case with my upgrade. My case has 5 fans which circulate a lot of air and help keep my processor cool. My new nVidia TI-4200 video board runs quite hot and has it's own heat sink and fan. There is a lot of heat to get out of the case and my system does well.

I hope this has helped.

Kevin, You're just a wealth of information! I was considering a dual processor b/c I'd heard that Photoshop 7 actually took advantage of the two processors. That's really the only reason I was even thinking about it. But, it sounds like perhaps that's not as much of an issue as other pieces of the system.

My two HD's are new within the past few months - Maxtor (bought one month ago) and Western Digital: both 60GB, 7200rpm, Ultra ATA/100. (Actually, I just checked - the Maxtor is Ultra ATA/133. But, if I remember correctly, the system will only go as fast as the slowest disk, right?)

Yes, I had already planned on getting a new case, since it seems that the power supply needs to be updated as well for the newer processors.

Thanks for all of your great info and wisdom. I [i]really[/] appreciate it! :D

Jeanie

Below is a copy of a message of mine to another list a few months back - which lists some basic real world results for two _similar_ machines that I use each day.

Remember that these results mean nothing to anyone except me - but it can be interesting to look into these sorts of things.

Basically - if your OS or application can use DP, then you will get a speed increase, but nothing near 200% or even 150% in most cases.

P.S. The benchmarking action I used did not use similar settings to my day to day production - so the time/speed may be a bit misleading (there can be a huge jump in time by using a 2 pix vs a 30 pix blur etc).

======

Unit A: G4 400, Single Processor, 370 Photoshop RAM allocation
Unit B: G4 450 Dual Processor, 230 Photoshop RAM allocation

After running a benchmarking action on both machines set to the same
nearest possible test conditions of each computer being at it's optimum
'real world' performance (chock full of apps and files and not defragged,
but with more than enough scratch for the tasks at hand):

50mb RGB Test File -

3.7 pix G/Blur:
Unit A: 25.6 sec
Unit B: 12.7 sec

85 pix G/Blur:
Unit A: 28.2 sec
Unit B: 13.6 sec

50/1/0 USM
Unit A: 12.7 sec
Unit B: 8.8 sec

Despeckle:
Unit A: 12.4 sec
Unit B: 8.5 sec

RGB to CMYK:
Unit A: 39.0 sec
Unit B: 37.3 sec

60% Image Size Width
Unit A: 4.2 sec
Unit B: 4.0 sec

There are more results and more tests to do (this is only part of the
benchmarking actions results), but it is obvious that even with less RAM
the dual processor running 50mhz faster will speed up many of my
operations (no real shock there).

So that's it - there's no real point to this post, just sharing my initial
findings on two real world computers (as in the past I have only had
reviews to go by and these are usually stacked or not real world setups).
This is not designed to test SP vs DP or I would have set both RAM the
same...it is just an attempt to see which of the two boxes I have access
to would be better to use as the main box - unless I am missing something
big it would seem that the dual processor is the winner for my work (which
is 99% Photoshop).

I found this interesting link while doing a search on MP Photoshop
http://www.reed.edu/~cosmo/pt/tips/Multi.html

It seems that the benchmarking action is not 'ideal' for me, since many of
it's tests are not 'real world' for my tasks - but it does provide some
good answers anyway. Can't recall where I got it from, probably a search
of the web for Photoshop benchmarking action or something.

I rasterize many Quark pages (selected elements) into Photoshop so that I
can perform seamless soft masking between elements that are usually alien
to each other (vector/raster).

Rasterizing a single or double page spread into Photoshop can be time
consuming, as the resolutions are often higher than normal - since the
Quark elements need to stay sharp (but 300 ppi is often acceptable), these
are panels and perhaps headline type - nothing really sharp or small, that
is left as vector in layout.

Rasterize 28 mb Quark EPS single page to 300 ppi CMYK:

Single processor - 71 seconds (half of this time is with the progress bar
stuck on 0%...then suddenly it churns through the data)

Dual processor - 44 seconds (instant rasterization progress with no stall)

Stephen Marsh.

I’m running dual and quad processor systems for 3 years and I use them with PhotoShop, Bryce 5 and more. Had no problems yet. I don’t know if I could ever go back to a single processor system.

Fascinating response from Adobe Stephen. Thanks for sharing that. Also, thanks for sharing your benchmarks. Of course, my frugal mind thinks a little differently. I'm trying to decide if, say, dual 1.4GHz Athlon processors would run faster than a single 2.53GHz P4. (There seems to be a significant price break right at 2.53GHz, where going up to a 2.8GHz is almost twice as expensive as 2.53GHz - therefore not worth it in my view.)

Trimoon/Steve - It sounds like you're running some pretty high-powered systems. And from what I know of Bryce 5, you're probably taking full advantage of them. To be honest, I find myself wondering what WON'T work if I get a dual processor system. Given my past 6 months of fighting with my current computer, I've become quite dependent on GoBack and not sure I'm comfortable giving it up yet - it's become my security blanket. Of course, if I've never used a dual processor system, I don't know what I'm missing, right? ;)

In any case, I appreciate all of this discussion!

Jeanie

Boy that is some good information. I didn't know that PS supported dual processors. Something to consider for the future. I knew that XP supported duals but PS is a plus.

Jeanie, the hard drive situation with the new IDE drives is that most of the good drives produced in the past year or two will have 7200 RPM and 8 MS access speed. What seperated them from the new generation is the higher capacity platters give them extremely high density. This high track density increases the actual data transfer rate because they can read and write much faster when the data is packed into a smaller area.

A real high performer would be a pair of these new IBM GXP120 drives on a Promise raid controller. I think that is my next upgrade path. There's never and end to how much you can spend on these PC's

Photoshop 5 or higher on Mac or PC supports multi-processors via plugs, judy like Altivec or MMX etc (I can't think back to v4 though <g>).

On the classic Mac OS, it is only Photoshop, Final Cut Pro and some other heavy hitters which use MP - and the OS itself does not...that's what OS X is for.

My benchmarks seem to indicate that dual processors with lesser RAM worked better than single processor with more RAM...but both of those dual processors are clocked 50mhz higher, so I am not sure if this is polluting the results or not.

Anyway...that was all a few months ago.

Since then the dual processors and most of the RAM have been moved to my main workstation, with the other computer being used to run a scanner and to do work on while the main unit is processing (truth be told, it plays music most of the time <g>).

I have yet to do benchmarks to see how much better things are now that the MP unit has more RAM than before...perhaps one day - subjectively I know things are now faster, but it is still painfully slow.

Stephen Marsh.

Thanks for the follow-up Steve.

I just realized something... Doesn't WinXP have a System Restore capability built into it? Does anybody know how it compares to GoBack? Seems like that might solve my issue of not being able to us GoBack on a dual-processor system!

Jeanie

Just started thinking about something else...

If I go with my current thought train of running two processors of a lower speed to equal a single processor of roughly the equivalent speed to the sum of the two, then any program which does NOT take advantage of the dual processors will run slower on the dual processor system than on the single processor, right?

My brain is working too much!!

Jeanie