SLI Water Blocks

[Dewave]

I have been building PC's for a long long time... And I hate these SLI water blocks where the top vid card simply feeds it hot water into the next vid card.... so.....

There are alot of after market water cooled blocks that feed the water from the top vid card to the second vid card... the second vid card will get hot water off the first vid card,,, no matter how ya slice it that is BS,,, it's always making the second card 5-10 degrees hotter then the first vid card.

If ya put a Y connector before and after the vid cards,,, the second vid card will always be cooler then first and both vid cards will over clock 5-10% higher.

 

[N H O]

err post this in the water cooling section?

 

[tbonem91]

I have been building PC's for a long long time... And I hate these SLI water blocks where the top vid card simply feeds it hot water into the next vid card.... so.....

There are alot of after market water cooled blocks that feed the water from the top vid card to the second vid card... the second vid card will get hot water off the first vid card,,, no matter how ya slice it that is BS,,, it's always making the second card 5-10 degrees hotter then the first vid card.

If ya put a Y connector before and after the vid cards,,, the second vid card will always be cooler then first and both vid cards will over clock 5-10% higher.

doesnt each card then end up with half of the original flow rate? which would (in most cases) severely impact the performance of the blocks...

 

[Talonz]

Eventually, the water in the loop will reach an equilibrium, making both cards have an equal temperature. I think the only way you would see a difference would be if you had a ridiculously good radiator/fan setup and extremely low flow.

If you use a Y connector and one block gets clogged more then the other, you could be in for a world of fun.

Also, this thread should be in Overclocking & Cooling -> Water Cooling

 

[nonlnear]

Actually, if one block gets clogged, you're better off with a Y. Cut your losses; at least with a Y one card won't fry. (But if you're watercooling a SLI setup, you can probably afford a decent safety system to avoid all that.)

But as to the original question, the total temperature change (in a reasonably high-flow setup) is rarely more than 1-2 degrees C. And that's between the hottest and coldest points in your loop. (If you want to experiment with this yourself, you can get the data that's relevant to your loop. And the places to measure the temps are near the two radiator barbs of course ) The hypothetical scenario Talonz said really is probably the only case where the temperature difference between the two blocks would be significant.

IMHO the best reason to go with a Y for SLI is if your rig has tube routing "issues". If you're having trouble making the turn for a serial loop, use a Y (especially if you're running 1/2" tubing and your mobo has the slots particularly close). The "halving the flow rate" argument is simply not true. You are decreasing the flow rate (not by 1/2), but there is more head pressure due to the blocks not being in series. The net effect on heat transfer is not that simple to tell without actually measuring temps. It might be slightly better, it might be slightly worse. Odds are it won't be much different at all.

 

[Adidas4275]

doesnt matter.... the entier loop is almost the same temp.... with in 2c of each other... if you are talking about core temps some core run hotter than others... they are not the exact same... hence different people getting diff temps on CPUs NB GPU and anything you can WC..

i have 2 inline temp sensors hooked up to my t-balancer and they are always with in 2*C of eachother... i wich i didnt spend the extra $25 on the 2nd one...

1st on is right after second radiator.... 2nd is after NB cooler... loop goes pump-240res-120res-temp1-cpu-gpu-nb-temp2-res-pump

 

[scwam]

Eventually, the water in the loop will reach an equilibrium, making both cards have an equal temperature. I think the only way you would see a difference would be if you had a ridiculously good radiator/fan setup and extremely low flow.

If you use a Y connector and one block gets clogged more then the other, you could be in for a world of fun.

Also, this thread should be in Overclocking & Cooling -> Water Cooling

I can confirm that my ghetto temporary sli watercooling is keeping temperatures within 1c of the other card at all loads. I say ghetto because I only have one fan running on my 2 x 120mm rad and the loop is messy, not the right mix of coolant/water, and everything is all crammed in a small coolermaster case atm.