Dual Quad 2GHz or Single Quad 4GHz

[TVFX]

Hi All
I have searched hi and low for a definative answer to this question and have read some very confusing material. The question relates to a machine I want to build for the purposes of 3D animation and visual effects.

The original question was what would render a 3D scene in Blender faster, a dual Xeon 8core computer running at 2GHz or a single i7 Quad core running at 4GHz?

After posting on some of the 3D and CGI forums I have realised it is probably best to come here and list the components that I intend to purchase and get some suggestions.

The question now is what "system"would better suit my 3D rendering needs

As I dont know much about the Xeon systems (apart from that they are designed for servers and are much more energy efficient) I am struggling to sort out other requirments such as RAM and MoBo, so suggest away.

Here are the specs I have so far:
Coolermaster HAF932 High-Air-Flow Design Premium ATX Gaming Chassis
TAGAN PLATINUM SERIES 1100W SLI & Crossfire Certified EPS Power Supply
Intel Core i7-930 2.8 GHz, 8MB Cache, Processor, Overclocked to 4GHz on a Gigabyte X58A-UD3R CrossFireX Mainboard
Corsair Hydro H50 Closed Loop Liquid Cooling Solution
6GB G.Skill RIPJAWS DDR3-2000MHz Memory in Triple-Channel Configuration
or
Intel® Xeon Processor L3426 (8M Cache, 1.86 GHz) and MoBo(unsure of model more research is needed and I'm open to suggestions)
Seagate Momentus XT Hybrid HDD/SSD
Quadro FX3400 with the i7 or Quadro FX1800 with the Xeons(dictated by Budget)
running Windows 7, Blender 2.53, Aftereffects CS4 and Sony Vegas Pro 9

Thanks in advance I eagerly await your suggestions.

 

[hans007]

i would usually take a single 4 ghz quad. however if your app is very memory intensive, you might be better off with the 2 slower quads since the ratio of your clock speed and memory would not be as large and thus the bottleneck not as big.

though i think that would be pretty rare. usually i'd go with the higher speed core because unless your application is very well threaded it (if its compute intensive) would be better off with just a faster core.

 

[3DVagabond]

Ok. Here's a couple of thoughts.

1, While rendering is the most time consuming process, it's not the only thing your rig will be asked to do. You will want it to be well balanced.

2, I'm not 100 percent certain about Blender, but most 3D apps. run single threaded when NOT rendering. For example, in the editing window or while running scripts, etc...

3, You're going to spend a lot more money for a 2P system. The processors are more expensive, the mobo will cost more, and you'll need twice as much RAM.

4, Most rendering engines are pretty efficient, but they don't scale perfectly with more cores.

Except for rendering the 4x 4GHz cores are going to run a lot better than the 8x 2GHz cores. Even while rendering You aren't going to get perfect scaling with the extra cores so it's likely the quad would be a little bit faster. That would likely only be a few percent difference though. The only case I can think of off the top of my head where the extra threads would be a benefit is in multi tasking. For example, if you were rendering, working in photoshop (Gimp?), and or modeling at the same time. Maybe with a couple more apps. running in the background. I sometimes run a separate UV app. along with my 3D app. and Photoshop. In those instances the 8 cores might well give you faster performance.

 

[TVFX]

[FONT=&quot]Great points, I completely forgot to factor in the modelling and animating stages. [/FONT]
[FONT=&quot]I do generally have other programmes up intermittently but usually I never render while I’m using them. I'm doing a lot of physics models like realistic fur and fluids and they are just taking forever on my current machine (12 days solid is the longest for 750 frames)[/FONT]
[FONT=&quot]I was leaning the way of a single high end quad but needed someone to give me a push. I can also afford to get the better quadro card with the i7 based machine.
Thanks[/FONT]

 

[jvroig]

I was leaning the way of a single high end quad but needed someone to give me a push. I can also afford to get the better quadro card with the i7 based machine.

If you still need any more push, then I can tell you that this is definitely the way to go. Not only will you have the better quadro card, you will have far better single-threaded performance, and you'd also have 8 threads on your "single quad" because of HT, (unless you turn it off for heat/power concerns after overclocking), so you really aren't in much of a disadvantage at all going the single quad route you specified.

 

[TVFX]

If you still need any more push, then I can tell you that this is definitely the way to go. Not only will you have the better quadro card, you will have far better single-threaded performance, and you'd also have 8 threads on your "single quad" because of HT, (unless you turn it off for heat/power concerns after overclocking), so you really aren't in much of a disadvantage at all going the single quad route you specified.

I have read that the Xeons have HT as well, but it doesn't really matter as I think the extra performance I will get during the modelling and animating stages will more than offset any gain during the rendering stage.

 

[jvroig]

Ah, you are right, I misread your model number before and thought it was a C2Q-era Xeon. Putting in your correct model, ark shows it has HT indeed

 

[JAG87]

The 2 GHz Xeon system would give you 8C/16T, and I doubt there are any 3D rendering applications that can make use of 16 Hyper Threaded threads efficiently. So in my opinion, to achieve fastest rendering times your best bet is the 4 GHz i7.

The only exception where the Xeon would a better setup, is if you need spare CPU cycles while rendering to run other applications. I'd say with the i7 you'd end up with 90-100% utilization during rendering, while with the Xeons you'd probably hit 80-90% of all resources. So you would have headroom for other threads.

 

[PlasmaBomb]

The faster single socket system will be faster...

provided you don't require vast quantities of ram (>24GB)