performance question.

[Les Therrien]

I currently have a P4 @ 2.0 GHz with 1 Gig of RAM.

I am considering going to 2 Gig RAM and possbily going dual processors.

I know that the Accurender portion of Revit will take advantage of the dual processors. My question is, if I upgrade these things, how much performance will I gain? Can anyone answer this question for me?
Thanks in advance.

Cheers,
Les 8)

[gregcashen]

I can't answer exactly, as I have not done any benchmarks. But I can say that I, Scott Brown and I think Mr. Zoog have upgraded to Dual Xeons with 2 GB and I have not experienced the breaking point yet. I did a tets render yesterday and then killed it after 30 seconds. It was much faster than my previous machine (if you can believe it 733MHZ PIII with 384 RAM) and quite a bit faster than my laptop or home computer (P4 2.6MHz 1GB RAM and PIII 1.5GHz 512 RAM, respectively). I have not come across any of the hardware acceleration issues with this machine. It has dual monitors too.

I got it refurbished from Dell (as did Scott and Chris, I think)

Sorry I can't be more specific :(

[Les Therrien]

Greg,

I am assuming that your Laptop Processor is an P4 "Mobile". correct?
Which would mean it's not a good comparison.

I talked to my tech. guy and he's trying to talk me out of the dual Xeon and to go with a P4 3.2 Ghz as apposed to my P4 2.0 Ghz. I told him that accurender does take advantage of the dual. However how much gain am I really getting. I know everyone thinks the performance is double but I know that is not true. How much gain is there?

He also said that going from 1Gig to 2Gig RAM wouldn't really do much.

But what I am seeing is everyone going from 1 to 2Gig RAM.

[gregcashen]

Ahhh, poor confused IT guys. I remember the days when there was "no point" in going over 33MHZz machines because the system bus maxxed out at 33MHz, so the processor could go as fast as it wanted, it was still only talking to someone that could hear 33MHz.

I have noticed a significant jump in processor availability at 2GB over my laptop, which is not a mobile P4, but a true P4. Keep in mind, that fans on the desktop are much more powerful and can keep the processors cooler than on my laptop, so they are running more efficient than my laptop is. Performance degrades exponentially/logarithmically or something with heat increases. Anyway, I am not a computer guru, so I don't make any specific claims about the individual performance benefits of more this or that. Subjectively, the machine screams compared to anything I've used before.

By the way, if XP is multithreaded, then if you use multiple programs at the same time, you will be able to take advantage of dual procs. I am almost always running Autocad, Excel, multiframe, woodworks, or enercalc when I am working in Revit.

[Les Therrien]

Thanks Greg!
You've been a great help.
Dual does seem to be the way to go.

[hand471037]

I've used dual proc machines for the last few years, my first being a P-233 Dual, actually my new laptop (ohboyhoboy) is going to be the first machine I've used in a long time that's NOT a dual proc...

Thing to remember with a Dual machine is that it lets you do twice the amount of work, it's not twice as fast. You'll get a minimal speed increase with non-multi-threaded programs, just due to the fact that the computer can devote an entire processor to the software when needed, moving everything over to the other available processor. Otherwise it's got to split tasks. So with a dual machine, it never stops to wait for something to finish, it's always cranking along, and that does, over time, add productivity.

For example, on my old dual Xeon at my old job, I would sometimes run two Revits side by side and have one rendering/batch printing while working in the other. Things like that are what the duals are great for.

The speed increase in Rendering can be large, it depends on what you're doing. For example, I don't know if Accurender uses both processors when calcing out radiosoty, but it does when ray-tracing. So if you're doing lots of interior photo-realistic stuff, and using lots of radiosity, and your software doesn't let you use both processors for that, then you just might be better off with one very fast processor than with two slower ones.

The biggest thing is still RAM, IMHO. When I went from the dual P-4 at my old job to a single P-4 at my new job they are the same speed, but the computer here has way less ram (512 to 2 gigs on my old machine). That drop in ram has made a huge difference, esp. with large projects. So unitl my laptop shows up, it's gonna be a little slower than what I'm used to.

So while duals rock, 2 gigs of ram rocks a lot more! ;)

[Les Therrien]

Jeffrey, thanks for the input.

I am sold on the the 2 Gig od RAM, no doubt.

So if I understand this correctly, regular revit functions will run at the ability of one processor!?

If I wasn't to do a lot of rendering (NOT) then I would be better off with a single P4, 3.2Ghz processor over a dual Xeon @ 2.4Ghz, correct?

:mrgreen:

[gregcashen]

That is correct, unless you run multiple programs simultaneously.

[narlee]

Where do you guys get your memory? 4AllMemory seems to have great pricing, with the BBBOnline seal. Any companies to look out for?

[Kroke]

Take a look at www.newegg.com or www.pricewatch.com
Good luck.

[TheDon]

Hi.. couldnt really tell from the thread - but if you have a "normal" P4 2.0, i.e., non-xeon, you won't be able to go dual processor. Only xeon supports multi procs.

TheDon
--------------------
Everytime I come around the corner Bling Bling

[sbrown]

The dual lets you read this newsgroup,email etc. on one processor while using revit on the other, so there is a little performance increase. The big deal is with rendering.