Help with building a number cruncher

Cycrow said:
if your doing a lot of floating point calcuations, have you through about using Cuda?
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I have thought about using Cuda. It's something I *might* look into in the future, but the vast majority of the code is already written to run on a standard CPU.

I know there are a few Cuda libraries for C# these days, and I'm hoping to have a look at them in the not too distant future.
 
MrWRC said:
Going off on a tangent here. If I was to go for the 3820, is that definitely worth the extra money over the AMD FX-8350?
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By a ridiculous margin. Heavy floating point operations are memory bandwidth constrained. The AMD chip doesn't really have any bandwidth. It also has one floating point unit per two cores, and the one it has is slower than the intel version. A quad core Intel chip soundly thrashes an eight core from AMD, even if you're looking at the dual channel 1155 systems.

I don't think the six core 2011 cpu would offer any benefit over the quad core one for the code I'm running. Yours may differ. In particular, if it takes four threads to saturate the memory bandwidth, do you have anything useful to do with the other two? There's also a fair price gap between the two chips which may be better spent on faster ram.

The corsair liquid cooler has about the same surface area as a normal cpu heatsink. Consequently it dissipates heat about as well. There's some advantage to the radiator being mounted on the side of the case in terms of airflow control.

Can you profile the code, see what steps take the longest? Upgrading hardware is an expensive way of working around bottlenecks in code. Especially if changes to how the data structures are stored and manipulated reduces the rather large ram requirements
 
@!bluetonic! - Thanks for the links, I'll take a look.

@JonJ678 - You sound like you know what you're talking about. Due to all the data being stored in a tree, I suspect I'll be hitting the RAM fairly hard as there will be a lack of cache locality, so I might just save myself a couple of hundred quid.

I need new hardware for several reasons, firstly, all my current hardware is a couple of years old now. Secondly, It's all in use, so I don't have anything spare to do the number crunching for weeks on end. The code is already very heavily optimised. Everything has been written for speed from the start.

Although.... is it worth looking at the 3930K over the 3820 due to ease of overclocking, or is this not a serious consideration? I'm a beginner when it comes to overclocking machines.

Thanks
 
MrWRC said:
Asus P9X79 Intel X79 (Socket 2011) DDR3 Motherboard
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I own this board and wouldn't recommend it for doing lots of high intensity work especially if you plan on overclocking. At stock clocks when folding with my 3820 the VRM heatsink gets hot enough to trigger the human "take your skin of the burney thing" reaction. If you check out the X79 Sabertooth (pretty much the same board with better cooling and a weird colour scheme) it has the same VRM heatsink but connected via a heatpipe to a second heatink with optional fan.
 
Ok, I think I'm getting there. The Sabertooth is a fair bit more expensive, but it sounds like it'll handle the heavy loads a bit better.

So, back to the CPU:
JonJ678 made a pretty compelling case for the 3820 over the 3930K... but is the 3930K a better bet for overclocking? Or will I be able to overclock the 3820 to a decent level with the Sabertooth X79?
 
Getting Expensive

Ok, well I'm ordering tonight. Last shouts if anyone thinks there is something I should change!
Asus X79 Sabertooth Intel X79 (Socket 2011) DDR3 Motherboard
Intel Core i7-3820 3.60GHz
Corsair Vengeance RED 32GB (4x8GB) DDR3 PC3-14900C10 1866MHz x2
SanDisk Extreme SSD 240GB 2.5" SATA 6Gb/s Solid State Hard Drive (So I can use it as a work PC when not number crunching)
Microsoft Windows 7 Professional SP1 64-Bit - OEM (FQC-04649)
MSI GeForce GTX 650 Black Knight OC 1024MB (CUDA enabled for experimenting in the future)
Alpenföhn K2 Mount Doom CPU Cooler
Western Digital Caviar Green 1TB SATA 6Gb/s 64MB Cache (For results dumping)
OCZ ZS Series 550W '80 Plus Bronze' (This seems to be recommended)
Xigmatek Asgard Midi Tower Case - Black
£1,506.88

The price seems to be slowly increasing
 
Looks good to me, might want to upgrade the PSU to around a 750W just for the future and to be sure - but that's being picky, a 550W should handle everything fine for now.
 
acme15 said:
Why are you going for the £270 Sabertooth over something like these for example?

YOUR BASKET
1 x Gigabyte X79-UP4 Intel X79 (Socket 2011) DDR3 Motherboard £209.99
1 x Asus P9X79 Intel X79 (Socket 2011) DDR3 Motherboard £190.99
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That decision was based on what was said earlier about the P9X79
I own this board and wouldn't recommend it for doing lots of high intensity work especially if you plan on overclocking. At stock clocks when folding with my 3820 the VRM heatsink gets hot enough to trigger the human "take your skin of the burney thing" reaction. If you check out the X79 Sabertooth (pretty much the same board with better cooling and a weird colour scheme) it has the same VRM heatsink but connected via a heatpipe to a second heatink with optional fan.
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It sounds like you think it's an incorrect choice? Do you have experience with any/all of these boards? Thanks.
 
MrWRC said:
That decision was based on what was said earlier about the P9X79

It sounds like you think it's an incorrect choice? Do you have experience with any/all of these boards? Thanks.
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How about the Gigabyte? Stulid rates it highly http://forums.overclockers.co.uk/showthread.php?t=18477529&highlight=X79-UP4+REVIEW

It's not an incorrect choice, just trying to save you a few pennies :)

Also I would recommend this PSU if you are looking at something around the 550W mark, however personally I would go for a 750W just in-case you wanted to add a more beefy GPU for CUDA work in the future :)

YOUR BASKET
1 x XFX Pro 550W Core Edition '80 Plus Bronze' Power Supply £54.98

 
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Thanks, I'm always up for saving a few pennies. Any ideas if I'd need low profile ram on that board with a big cooler?
 
MrWRC said:
Thanks, I'm always up for saving a few pennies. Any ideas if I'd need low profile ram on that board with a big cooler?
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It depends how big you are thinking really, but you would generally need low(ish) profile RAM on any motherboard if you are thinking of installing something huge like a Silver Arrow.

I'm not sure of the specifics for memory clearance on each individual cooler, but it wont be dependant on the motherboard.

Here are a couple of options for low profile 64GB:

YOUR BASKET
4 x GeIL EVO Leggera 16GB (2x8GB) DDR3 PC3-17000C11 2133MHz Dual Channel Kit (GEL316GB2133C11DC) £129.95 (£519.80)
4 x Adata XPG Xtreme v1.0 16GB (2x8GB) DDR3 PC3-17100C10 2133MHz Dual Channel Memory Kit (AX3U2133XW8G10-2X) £119.99 (£479.96)

 
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