|Watercooling: Taking the Plunge|
I've recently built a new PC:
CPU: Core i7 920 (2.66 Ghz)
RAM: 12 GB RAM (OCZ 1666Mhz)
GPU: 2x NVidia GTX 280
MB: Gigabyte EX58-EXTREME
Couple of hard drives, DVD writer, etc... all the normal stuff.
I've successfully overclocked the 920 to 3.2 GHz stable on air. I've got a pretty crappy fan (Thermaltake V1) on the CPU but temperatures are within acceptable ranges. I haven't really pushed it farther than that yet. I can boot at 4.0 GHz and 4.2 GHz but it is definitely not stable because of heat.
I have not overclocked the 280s yet because they already run really, really hot.
I've never watercooled a PC before, and am considering it. The motherboard already has built in blocks and heat pipes for the north/south bridge, so that's taken care of.
That leaves the CPU and GPUs. I'm considering starting with just the CPU and the north/south bridge, but buying a big enough radiator/pump to eventually do the whole system.
The GPU blocks are ungodly expensive (the two of them would almost be as much as one of the video cards). I also want expandability into 3x SLI should I decide to go that way.
Any suggestions or tips?
Just out of curiosity: what are you going to do with such a mean machine?
Why do you think a webmaster should be overclocking?
This is not a webmaster tool, more like a gaming Ferrari :)
One thing to consider is that the water may become contaminated with algae and sludge may fill the smaller holes blocking cooling after some months. There are special additives to prevent that.
|This is not a webmaster tool, more like a gaming Ferrari |
That would be puzzling considering what this site is about.
|Just out of curiosity: what are you going to do with such a mean machine? |
I do a fair bit of data processing from large web logs on my local machine as well as some gaming. The data processing is very much helped by the additional CPU power and RAM. I'm interested in also looking at CUDA to see if there is some use there for data analytics.
|Why do you think a webmaster should be overclocking? |
I don't necessarily think a webmaster *should* be overclocking. But it's a hobby for me. I overclock for the same reason someone might climb a mountain - it's fun and challenging.
You can also get some great bang for the buck when you overclock, considering what Intel charges for its latest and greatest CPUs. If I can gain 60% advantages (from 2.6 to 4.2 GHz) in CPU intensive data processing tasks, it's a massive increase in my productivity on a day to day basis, especially considering most applications have yet to use multiple threads effectively.
|This is not a webmaster tool, more like a gaming Ferrari |
Thank you lammert. I will take that as a compliment. ;-) Being serious though, there are a lot of surprising applications coming out for those that use them as secondary and tertiary processing units... for now it's mostly CAD, but nVidia is pushing hard with CUDA to move it more into the mainstream.
The ATI vs. nVidia is an ongoing debate right now, mostly because you can get an ATI solution at 90% of the performance of the nVidia solution at about half the price. That said, I have an affinity for nVidia, am still scared of ATI because of their issues with drivers in the past, and CUDA support as mentioned above.
Things like this really interest me: GPU Quicksort Library [cs.chalmers.se]
Tests shows that it can outperform highly optimized CPU-based Quicksort with a factor of 10 on cards commonly available in 2007. Sorting 16 million floating point numbers or integers take less than half a second!
|There are special additives to prevent that. |
I'm also a hobby saltwater aquarist. That's the first thing I thought of, but as you said, there are good additives for that.
I ended up going with a thermoelectric cooler specifically for the CPU (it's self contained), and a separate watercooled loop for the 2x GPUs and the MB. I built the loop last night and it's currently testing for leaks. Nothing so far. I'll let it run until I get home tonight and then put her back together and start her up.
[edited by: bakedjake at 5:03 pm (utc) on April 27, 2009]
The gaming Ferrari was a compliment :) Each of those GPUs has 240 separate multi-threaded floating point units if I remember correctly. That is 480 parallel multi-threaded calculations.
For this kind of data cruncing I use a Playstation PS3 running Linux. Lots of parallel processing power also, but somewhat restricted in memory and disk speed. And the main double PowerPC core in the PS3 doesn't have as much power as modern multi-core Pentium CPUs.
Thanks for pointing out CUDA. My main desktop contains a Quadro FX370 which also seems to support it. I have some number crunching projects where I haven't decided yet on the hardware and replacing a PS3 with a more mainstream PC and high performance graphics card may be a good alternative.
|more mainstream PC and high performance graphics card |
lammert, if you're not using the graphics card for graphics, you may want to consider nVidia's Tesla [nvidia.com]
240 cores, but with 4 GB of RAM. Good if you're doing pure number crunching or rendering and don't need (or already have) video.
I still game occasionally, however. :)
Thanks for the info about the Tesla. I have already downloaded the SDK and will start testing soon on my "crippled" FX370. When ready the system will actually be running as a public accessible website, something like an on-line gaming system, but no real gaming. I only won't do the water cooling like on your system. Not many data centers currently support water cooling. ;)
Now I just have to find a data center which provides at least 1000 Watt sustained power for a colo server with 4 Tesla boards.
|Now I just have to find a data center which provides at least 1000 Watt sustained power for a colo server with 4 Tesla boards. |
You may want to roll your own box and co-locate instead of going with an off the shelf solution from a provider. There is very little off-the-shelf anything for Tesla.
1000W is not too uncommon to see these days (all brands make modular versions to 1000W), and I think I even saw a 1600W on the shelf last weekend at a store, so if you're comfortable building it shouldn't be all that hard to build a machine for Tesla.
Just take note that all power supplies at a rated wattage are not created equal so do your homework. This is an especially important point for any nVidia card made in the last 18 months or so; they need lots of stable power or else you will run into issues. You'll find that nVidia's recommendations tend to be quite a bit above what they actually need; this is due to the fact that there are so many bad power supplies out there.
Also, don't think of putting this machine on a small UPS. The machine I built above (even on air) will not run on my 1000VA UPS at home. ;-)
It looks like you have to go AMD to get 4x PCI-e slots right now. That is going to be one hot, hot machine. My GTX 280s run at 70-80C on stock air at decent load and 100% fan (you can tweak fan speed). Another reason to roll your own - you'll want to make sure you have good airflow in this machine.
Just make sure to send me pictures, lammert. ;-)