Watercooling Isse

Bucks85th · 15 Mar 2011 at 22:05

Thanks Confused!

I'll try & have a look at the blocks at the weekend when I have a little more time.

Given the GPUs are at similar temps at idle, but 1 is hotter than 2 under load, would this not be considered usual? I'm thinking that the water going to the 2nd block is already warmed by the first GPU (they are next to each other on the mobo and joined by an adjustable length SLI barb.

If I reversed the fans on the rad to suck in air, would I not then also be better mounting them above the rad or are they OK still underneath the rad and sucking through it? Trying to mount them above the rad may prove to be tricky!

Cheers!

Jim

JeffyB · 15 Mar 2011 at 22:39

Remember when choosing a rad to make sure you pair it with fans that suit it's characteristics. The BI Gtx series have very high fins per inch (fpi) and will need fast, noisy high pressure fans to get the best from it, anything below about 1400 rpm and you will not see the benifit of the extra fins. Conversely low fpi rads work better with slower moving fans and suit low noise systems, the sr1 series are about the best in this category. The best alround rads are the thermochill ta series and the xspc rx series.

cammy5477 · 15 Mar 2011 at 22:55

Bucks85th said:
Thanks Confused!

I'll try & have a look at the blocks at the weekend when I have a little more time.

Given the GPUs are at similar temps at idle, but 1 is hotter than 2 under load, would this not be considered usual? I'm thinking that the water going to the 2nd block is already warmed by the first GPU (they are next to each other on the mobo and joined by an adjustable length SLI barb.

If I reversed the fans on the rad to suck in air, would I not then also be better mounting them above the rad or are they OK still underneath the rad and sucking through it? Trying to mount them above the rad may prove to be tricky!

Cheers!
Jim

yes as i already said in previous post suck cool air in from the top and exahust it out the sides.....your fans will work better if you turn them round (still on the bottom of rad) and pull air through the rad

and yes again what you have said about both being same at idle then 2nd hotter on load makes perfect sense and will explain what your seeing

Sc00p007 · 16 Mar 2011 at 03:50

Loop order will not affect the temperatures as much as you think. As long as the reservoir is the component before the pump, the rest of the loop order will not matter. The temperature of the water anywhere in the loop will be around the same give or take a degree or two.
The water is not in the block long enough to significantly heat up the water. The water travels around the loop slowly rising in temperature on each lap before it equalises.

Phil.

Bucks85th · 16 Mar 2011 at 08:07

Thanks Chaps,

The pump & reservoir are housed in a single perspex dual bay box. So the pump sits in one half, and the reservoir the other.

Cheers!

Jim

JonJ678 · 16 Mar 2011 at 09:46

Your cpu uses around 200W, Google tells me the TDP for a 580gtx is around 250W.

A thick 360 rad has a C/W value of 0.02. If we assume your radiator is 50% worse (I haven't checked this figure), then your equilibrium water temperature should be (200+250*2) * 0.03, that is 21 degrees over ambient. This isn't great, but it's not terrible either, and I think I'm overestimating it. Worst case temperature rise across your cpu block if correctly mounted is 30 degrees, so I believe your cpu should be at 50 over ambient.

Assuming your room isn't at 40 degrees, I believe there is a problem with your set up, rather than the hardware. Some of the above posts have dealt quite well with that side of things, if you've remembered the spacers (or used short threaded barbs) for the appropriate side of the gpu blocks then my money's on air in the radiator.

That said, were I in your shoes, I'd take the cpu out of the loop and fit the H50 back to the board. It isn't the ideal solution, but it'll outperform the current set up without additional cost.

Bucks85th · 16 Mar 2011 at 22:46

Thanks Jon!

Some good news! After 3 hours of ArmA2 tonight, I saw a max temp on GPU1 of about 68-69 degrees. CPU got into the low 60s. Room temp was about 22 degrees.

So I will be taking all your advice and getting a 2nd rad, re-checking all blocks, and reviewing the airflow before I start looking to o/c the GPUs.

Once again, many thanks to you all for your time & help!

Jim

Bucks85th · 8 Apr 2011 at 22:32

I have finally got everything together, and whilst there are still a few bubbles to iron out, it's running like a dream.

This is the 1st time I have tried this, so once again, many thank to all for you advice!

OLDPHART · 8 Apr 2011 at 22:47

Nice job.

LiamJ · 9 Apr 2011 at 00:09

The temperatures?

Bucks85th · 9 Apr 2011 at 00:12

GPU1 is idling at about 42
GPU2 at 37

CPU at about 41

Ambient room temp is 26

Bucks85th · 9 Apr 2011 at 07:57

Seems to be running at about 13 degrees above ambient when idle.

Unfortunately, the room it's in is a bit of a sweat box and due to the insulation stays hot in the evening. Switching on this morning I am looking at GPU1=36, GPU2 = 32 and CPU = 39.