Thats a good question and I'd like to know aswell, or even the 3rd in a Tri set up.

The last card in my loop is about 3-4 degs hotter on idle and under load.

Odd, mine all run identical temps. They should be the same because water temp shouldn't vary throughout a loop more than a couple celsius. If you have a large variation, you probably don't have enough flow. Even my 3, 6970's were all within 1c of each other under load.

I don't think flow is a problem (got a mcp 655 in there). Is your loop parallel or serial. Mine is serial. I acutally have temps within 1 deg of each other during idle. However, during load it will be a bit different. Also, the hottest card I have also happens to be the "flashed 6970" which is running a fairly high oc while the other two are not.

mine is in series. I think you just found your cause though. The flashed 6950 probably just runs hotter since it is overclocked from stock speeds.

1: The radiators are rated to dissipate up to 700 watts of heat a piece for the GPU loop, but in order to hit that kind of heat dissipation, require the fans to spin at RPM levels that you can hear them if going for maximum overclock attack mode on the cards, wich will release more heat at higher clocks, so it comes down to ajusting the amount of radiator surface relative to how much you can tolerate the sound of the fans,and of course the amount of room available in the case(if the idea is to have everything installed internally)....The bigger the surface area, the slower the fans need to spin to achieve a given cooling capacity, the quieter the system overall.


2: Way more than enough for just 3 cards, especially if using a push/pull configuration on the radiator....4 fans on either side of the radiator and colder outside air being pushed in first, while the other 4 fans on the opposite side pull it out of the radiator itself .


3: look at the picture for the video cards, and you'll see 2 tubes linked to each one, and the intake on the top card and the exit at the bottom card...They're basically setup in parallel so that all 4 cards receive cold water at the same time and it doesn't go from one card to the next with a single pipe bettween each card(in series), so temperatures on all 4 cards, even under load are the same, and there's less restriction on the flow itself, so more water flows thru the cards to begin with.


It took over 30 minutes of heaven benchmaking with the cards overclocked to see the 4 cards stabilise at 62*C under load and stay there....They started out at 52*C at the begining of the first run, so tempertures rise very slowly and gradually and still well below what the stock air cooler would be doing when overclocked....

Thanks for the info guys! Much appreciated.

The current 6990 fan sounds like a jet engine when going at full blast so any reduction in noise level will be nice. I'm still contemplating on going liquid with Tri 7900, either a 7990 + 7970 or 1x 7970 DirectCU II + 2x reference 7970 (to get at least 3x DP outputs) and I'm in the process of researching if a 560mm rad is sufficient. Thanks Shadown for the clarification on how the waterblocks work on multi-GPU configs as I was wondering on the end result. Also thanks for your push/pull advice on the rad but I suspect that would make the thing too wide to internally mount inside my case. Need to do some measurements. :)

Radiators come in 4 types in terms of how thick they are:

30 millimeters.
47 millimeters.
55 millimeters.
64 millimeters.


Regular fans add 25 millimeters to either side of the radiator, so in the worst case scenario with the thickest radiator on the market, that's 11.4 centimeters of space needed(4.5 inches), but keep in mind you have to figure on how you'll mount it if it's done internally too.

Once you go wc on gpus you can never go back. the 7990 +7970 much cheaper route gpu wise and block wise.

How did you screw in those screws in that radiator sandwich? Needle nose pliers? I checked home depot for some hex head 6/32 screws but they didn't have any.

Did you go inside or did you just check their website?

When I went in my local HD I found many screw components not listed on their website.

The radiators use metric threads with EK, and they're 3mm Hex bolts and yes, i used a needle nose pliers for the locking nuts while using a 1/4 inch ratchet with an extention and sockets with a built in flexible joint on the bolt itself.

I went in the store. I've never been impressed Home Depot's hardware section. The Ace Hardware that I worked at when I was younger had a wider selection of miscellaneous screws, nuts, bolts, etc.

For example the one time I went to home depot in search of a small bolt and the smallest that they had was a standard 4-40 which was too big.

Thanks for the info. While I was in the Home depot I did see small hex head metric screws. Sadly didn't see any 6-32 hex head bolts though. I guess that I'll just use a nut right under the screw head. Should still be small enough, hopefully.

I had to hunt down quite a few hardware stores to find metric screws even though i live in canada and we've converted to the metric system for a couple of decades now....Finally found some at a corner no name hardware store close to home, run by a 70 year old guy that owns the business and it's been there forever....:lol:

Even then i had to cut some of them down as they were a bit too long and use a file to smooth the threading on the end of the bolt and make it usable again.

My case is about 22cm wide and I'll only have half that space available for the 560mm radiator (the other half for the PSU which is mounted on its side) which will take up the entire length of the case. What's your opinion on push/pull on a thinner radiator vs push only on a thicker radiator?

Excellent idea. :up: It didn't come across my mind that I'll be saving a GPU block if I do 7990 + 7970. :o

What case is it and it would give me a better idea if you posted a picture, but with the PSU mounted on it's side, it takes up 9 cm right off the bat, so that leaves 13cm, so you still have 1.5 cm of room with the widest radiator on the market and a push pull arrangement.

The main issue here is if the PSU fan is an intake fan to cool off the PSU, and if will it be facing the direction of where the radiator will be located...The radiator is going to release a fair amount of warm air right into the PSU and making it work hotter.


One option might be a dual 360 radiator setup mounted between the PSU and the front of the case with fresh air coming in from both sides of the case, and exausting that hotter air it from the top and rear and front fans...in terms of flow both would be connected in parallel as far as water flow goes, and there radiators with ports on both sides, like this:





You see 2 ports on the top but there's 2 more on the other side, and even a drain plug on the very bottom....Makes it handy to empty the system.

My case is a SilverStone TJ11. These 2 photos should probably give you a better idea of how it looks currently.



The case can apparently house a 560mm radiator. When I eventually get the 7990 + 7970, I'm thinking of having the 560mm radiator on the side where the 240mm radiator (for CPU) currently resides, and move the 240mm radiator to the other side of the case in front of the PSU. FYI, the 240mm radiator is a Swiftech MCR220-QP which is 37mm thick. Thinking of having separate loops for the CPU and GPUs with probably 2x XSPC dual bay reservoir to make more space in the lower compartment for the radiators.

Nice case!

A full lenght 560 should fit in there nicely, though the thickest version might be a tight squeeze with a push/pull setup on it, and the PSU right beside it, but at least the intake fan for the PSU isn't pointed in the direction of the radiator

Thanks! I was going to keep my old TJ09 for this build and didn't plan to get a new case. But when I started to work on it, I realized that my new motherboard is XL-ATX which doesn't fit in a standard ATX case. :o Having had it for almost a month now, I really like this case and an added bonus is that it opens many possibilities in terms of liquid cooling. :)

The PSU can be mounted in either orientation so it's all good. As you've pointed out, a thick rad will likely be a tight squeeze. What do you think of push/pull on a thinner radiator vs push on a thicker one?

Radiator thickness doesn't really make a difference. How many fins per inch and fan speeds matters more.

If you have a 34m radiator with 20fpi and a 68mm radiator with 10fpi, they should perform the same with identical fans.

I am contemplating on a new case for my new build. I was thinking of going case labs but I prefer the standard tower look. I am looking into the tj11 as well. Would really like to see one in person but no where has one in store near me.

Most overpriced case I've ever seen. $659.. rofl

remember the coolermaster airbrushed cases that were over $1K?

At least those were airbrushed. :bleh:
Those cases being 1k+ doesn't make this case at $659 any better. :bleh:

Not even including shipping.

Switched back to 120mm fans, I don't think I will go back to 140mm until there's a Gentle Typhoon equivalent of that size.



I also got rid of some leaking rotary fittings.

It's amazing how much bigger the case looks without the divider plate like in the 800D

Thanks. I'll bear that in mind when I go radiator shopping.

I guess most of the shops won't be stocking this case given its price. I live in Hong Kong and none of the places have it here. I had to call up the local SilverStone distributor to have one delivered directly from their factory in China. :lol: I wouldn't say this case is worth every penny because it is not. But I can say that this case is solidly built and makes my old TJ09 feel flimsy by comparison. One overlooked aspect of the case is that it is built entirely with screws without even one single rivet. So for those with some imagination and skills with their hands (both of which I lack), the case can be modded to something pretty nice looking ones like this and this.

Hater... Do I need to apply for your budget approval when I purchase my next piece of overpriced whatever? :lol:

It kinda pisses me off that he makes those statements, like calling someone else's piece of hardware over priced. When you realize how old he is, and what kind of system he has, you know he did not buy. Probably got it for his birthday. Or took an advance on his weekly allowance.

Final build shot: