Watercooling 2x7800gt's (BFG OC's) in SLI

pastymuncher · 17 Jan 2006 at 15:49

Hi there. I am looking in to watercooling my pair of BFG 7800gt's as i am fed up with getting cooked in front of my pc. The damn noisy things were pushing hot air against my front 120mm intake fan and cooking my hard drives, so i had to reverse the front fan to suck air out and so it blows straight at me. Anyway i have been thinking about it for a while now and have been looking around to see whats what.
I have an ordinary sli board so the gap between the two cards is about 2 inches if that.

Has anybody got a watercooled 7800 setup at all? If so how have you got it rigged up (have you got the outlet from one card straight into the inlet of the other so that the second card presumeably runs warmer or, have a Y piece and created two loops that join back together after the gfx cards) and what components do you use?

Waterblocks wise i have been looking at the following:-
Alphacool Nexxxos WAK GFX NVXP-3 6800/7800 vga blocks,
Koolance VID-NV2-L06 6800/7800 vga block,
Swiftech MCW-55 vga block,
DangerDen NV78 7800 GPU SLI KIT Rev 1 - for 256Mb Cards (1/2")

Apart from the Swiftech and Dangerden blocks the others seem to be only 1/4" pipes which seems quite restrictive to me. That Dangerden kit is expensive too, £135.04 just for the two blocks and the fittings. The Koolance got a good review over on systemcooling.com and it cools the memory as well. I have been assured it now fits the 7800 series too.

Any other good blocks i have missed?
I really wanted to use 1/2" tubing for max flow. For the pump i was thinking of the Eheim 1250 1200 l/ph mainly as i keep fish and use Eheim products i know how reliable they are, but am open to suggestions.

I want a triple 120mm rad and came up with these:-
Thermochill PA120.3
Alpacool Nexxxos Pro lll triple rad,
Alphacool Nexxxos Xtreme lll triple rad,
Waterchill RDT02 triple Black Ice Pro lll.

All this will be in a box bolted to the underside of my desk with only the tubing to and from the blocks (and the blocks of course) inside the case. Is it worth paying the extra for Tygon tubing or will the normal stuff do just as well. Only the gfx cards will be cooled by water as i am more than happy with my SI-120 on my cpu.

As for routing i was thinking of putting a Y piece before the gfx cards and splitting the feed between the two cards so they will both recieve water already cooled and then joining them back into one with another Y piece on the return side of the card before the radiator. Or does it not make a lot of difference with one card having the first cards warm water going through it? I was thinking of two seperate loops at one point.

Sorry if this is long and drawn out but i want to get this right first time. Many thanks in advance for any advice.

pastymuncher · 18 Jan 2006 at 10:44

Thanks for that Arcane, pretty decent temps actually. I know mine are hitting 36 for gpu 1 and 46 for gpu 2 on idle and in the 50's and 60's loaded.

Anybody else? Everyone is always going on about watercooling so lets here from you. I don't want to dive in here and hope for the best.

pastymuncher · 18 Jan 2006 at 11:14

I know. It's £135.04 for a pair in an sli kit which is better than buying two seperate blocks i suppose as you do get the fittings as well, but it's still a lot of money. That's why i was looking at the others too. The only thing is though that apart from the DD and the Swiftech MCW-55 the other two are only 1/4" bore. I am not sure that the swiftech block will even fit in sli.

There are also some blocks i found that don't even fit the BFG's for some reason.

pastymuncher · 18 Jan 2006 at 11:29

Same here which just leaves the DD (1/2"

) and the Alphacool Nexxxos NVXP-3 (1/4"

).

Edit
Just found the Alphacool in 1/2" for £45 each.

pastymuncher · 18 Jan 2006 at 14:50

I have a Thermaltake Armour (22cm wide) so it may not be a problem. I am leaning towards the DD maze 4 low profile gpu blocks and using ramsinks for the memory. It seems to have worked well for other people on other forums.

pastymuncher · 19 Jan 2006 at 09:39

Sorry 22cm wide. Good grief, if it was 2m wide it would take up the whole desk. :eek:

In fact it would be a squeeze to get it in my little computer room at all.

I don't think the ramsinks will be in the way as they go from one side of the gpu, around the back and down the other side. I have seen picyures on another site with the LP maze 4 and ramsinks fitted. Competitoe so i can't give you a link. Looks the business though. People on the other sites forum have been getting temps in the low 20's at idle and low to mid 30's load with this setup. At £35 each or £74.99 for an sli kit with all the ramsinks and fittings thats almost half the price of the DangerDen NV78 7800 GPU SLI KIT.

pastymuncher · 19 Jan 2006 at 10:21

Bugger!! Just looked on DD's website (what an awful site) and it says you have to "modify" the ramsinks under the fittings. I guess that means you got to chop the tops off them. Not happy about that. Seems to defeat the object. Back to square one again. :confused:

pastymuncher · 19 Jan 2006 at 14:14

Yeah, 22cm. Don't know how i got 220cm. :rolleyes:

Had a look at the Silverprop but it does'nt state compatiability for 7800's and the fittings are even lower than the Maze 4's. Probably going to go for the Maze 4 sli kit for £63.34.

pastymuncher · 19 Jan 2006 at 15:33

I found them on a similarly named retailer and the HL (taller one) has a month delay but the SL (lower one) is in stock but a similar price to the DD Maze 4, but then i would have to buy 2 additional adaptor kits on top.

I have a shortlist now anyway:-

Danger Den Maze 4 LP SLI kit
Eheim 1250 1200lph pump. (would have gone with the DD D5 but can't find it in stock).
Alphacool Nexxxos Extreme lll triple radiator.
Cape coolplex 10 external reservoir.
7/16" masterkleer tubing.
A flow indicator, not sure which yet.
A temp indicator, Ditto.
Deionised water, probably Halfords.
Some additive, also not sure which. Need to read up on that.
Chrome 1/2" fittings for the rad, pump and reservoir.

I have decided to run both cards in parellel so one does'nt get the hot water from the previous one. So i will be putting a Y piece in as the hose enters the case and splitting the feeds to the cards and another Y piece after the outlet from the cards to join the feeds back into the return line back to the rad. Should work anyway.

I have decided to go for 7/16" pipe and 1/2" fittings so that the pipes id is slightly less than the od of the fittings and should give me a good tight fit (after heating the pipe) and hopefully i won't need any pipe clips.

pastymuncher · 19 Jan 2006 at 20:00

Not planning on doing the cpu at all. I got a SI-120 on that with a Thermaltake Thunderblade 120mm fan keeping it down to 31 idle/42load which i am quite happy with.

I just want to get the heat from the two BFG's out of the case as my case temps are shooting up and the heat coming out the front of the case is cooking me.

pastymuncher · 20 Jan 2006 at 10:45

Hi again. It's on the DangerDen website but i don't think i can paste you a link as it's on the page where you can buy the Maze 4's.

pastymuncher · 20 Jan 2006 at 20:08

Decided to go for my shortlist from above. Still trying to find a DD D5 pump in stock though at a reasonable price. It's a hell of a lot smaller than the Eheim 1250.