watercooled gf 6800 gt SLI setup

[Mallus]

Im building my self a new rig with 2 GeForce 6800 GT PCI-e SLI cards.
I was planning to Watercool it, but I ran into a problem the space between the graphics cards is limited(4 cm center PCI-e(1) slot to center PCI-e(2) ) so i was wondering if there is anyone who Knows a solution to my problem (And uhm normal Cooling isn't a option.)

Here is some info about the rig

AMD Athlon 64 3500+
MSI K8N Diamond
Dual GF6800 GT PCI-e SLI
2 GB Ram
300 GB SATA HDD 16MB

[Frakk]

just what you need my firend:
http://www.dangerdenstore.com/product.php?productid=168&cat=48&page=1

[Guttenaffe]

jeze, your going to have to have more than one water circuit or at least one big ass pump and tons of radiator cublic inches with high air flow to gain any benefit…

[Mallus]

That is exactly what I planed 1 circuit for the cpu+chipset and a circuit for the 6800's :)

[Xato]

i hate you people and your money... lol
the computer shop i worked in closed =(

but as far as the pump goes, it doesn't matter how fast the water in your system goes, as the slower water passes the heat source, the slower it passes through the radiator. Thus you end up with warmer water, that has more time to cool down. Thus both effects cancel eachother out...
Allthough, one big ass radiator would be required for an all in one solution... lucky ur not tho =P

What i did notice is that the GPU waterblocks run in sequence, as do most cooling systems, but wouldn't you have more stability by having the waterblocks in a parallel system, so that both chips are at the same temperature, rather than one sucking heat off the other?

[Frakk]

it doesn't matter how fast the water in your system goes, as the slower water passes the heat source, the slower it passes through the radiator. Thus you end up with warmer water, that has more time to cool down.
this is not true. each molecule of water spends the same time in the rad no matter how fast it flows. if its slower, it spends more time in it per cycle of course, but the faster it goes, the more cycles it goes through in the same period of time, therefore it doesnt make any difference in this matter. however, the slower it flows, the less efficient it gets taking the heat away.

i wouldnt worry about the system in parallel or not, it wont make a huge difference considering the fact that the gpu's will be parallel to the rest. for an sli system danger den's solution seems to be the cleanest but not the cheapest. there is the other, cheaper solution here (http://www.dangerdenstore.com/product.php?productid=169&cat=48&page=1). If you want them in parallel, this is the way to go and it is cheaper, but you'll have more tubing work to do. either way, you'll end up with a nice system if you make the effort.

about the poll: i think you'll have to decide about the looks:)
for functionality: the 2x Maze 4 blocks will not cool the memory on the card, only the gpu, but you can set them in parallel. the 6800 sli blocks will cool the memory for better overclocking. you could also get 2x nv-68 blocks and put right angle barbs in them and have them in parallel just like the Maze 4 blocks. I think there is enought room, but i would check with dangerden just to make sure.
to sum it up: if you have lots of money and want to overclock, id get the 6800sli blocks (or 2x nv-68 with right angle barbs in parallel if possible), if you want to save for other components, go with the dual Maze 4 and some ramsinks.

[Xato]

this is not true. each molecule of water spends the same time in the rad no matter how fast it flows. if its slower, it spends more time in it per cycle of course, but the faster it goes, the more cycles it goes through in the same period of time, therefore it doesnt make any difference in this matter. however, the slower it flows, the less efficient it gets taking the heat away.



Lol, that was generally what i was trying to say =D in the end both effects cancel each other out, as both heating cooling of the water is based on a fraction of their cycle, which inherantly remains the same. Although i do see your point with the effeciency of taking the heat away, as the heat source is not a singular point and the faster water passes over it, the less it will retain its own heat.

As far as parallel and series water cooling goes... i was just being finiky :p
i must say, i think parallel WC on those GPU's would look sweet.

[Frakk]

Xato sorry if you were trying to make the same point but what i understood was that u think slower the water the better it performs because it has more time in the rad. now i read it again and i get it lol. however the faster it flows the better it performs :D

[Xato]

lol yeh, its all cool. Though we must remember, pumps add heat too! so beefing out a system with pumps wont cool it down =D

[Frakk]

beefing out the system with pumps wont make the water go faster either :D

neways any progress Mallus? :D

[Xato]

This polls a tight one!

I think the All in one GPU is cleaner, but the idea of the Twin set is cooler... =P

I'm sure both will looks very cool though.

[Mallus]

neways any progress Mallus? :D
Im planning to start a worklog this weekend so stay tuned.

I will go for the Nv-68SLI setup with a DD 12V D4 pomp
and a Black Ice Xtreme III Radiator and for the cpu a MAZE4.
And I wasnt planing to overclock it yet. but you never know.

I hope this will do.

O and it will be sometime before the DD stuff arives at my home. they told me it will take about two weeks.
DD is hard to get here in holland.

Edit: the rad will be a Thermochill 120.3