help me pick blocks for my GTX295s

[SteveRo]

I decided not to wait for the single PCB version.
Two PCB vs one PCB - indications I was seeing was same specs, maybe running a bit warmer (due to closer GPUs) and not as robust power circutry.
So I have 2 EVGA GTX 295s on a Gigabyte x58 extreme with i7 965.

Cooling will be a bit unique - to start with - a single loop as follows -
Mcp355 pump with xspc reservoir top – boreas – boreas – GTZ block – GTX295 - GTX295 - pump (all 1/4 inch, I will probably play around with this over time, 1 vs 2 loops).

So what are folks using for GTX295 water blocks, advantages, disadvantages?

What are folks using for connectors between GPU blocks, advantages, disadvantages?

http://img42.imageshack.us/img42/56/dsc02536h.jpg (http://img42.imageshack.us/my.php?image=dsc02536h.jpg)


http://img39.imageshack.us/img39/6682/dsc02548q.jpg (http://img39.imageshack.us/my.php?image=dsc02548q.jpg)


http://img34.imageshack.us/img34/4295/dsc02549a.jpg (http://img34.imageshack.us/my.php?image=dsc02549a.jpg)


http://img37.imageshack.us/img37/309/dsc02550.jpg (http://img37.imageshack.us/my.php?image=dsc02550.jpg)

[b@llz0r]

im using EK blocks on my 295s, temps are good, the only drawback for me is the internal design wont let me hook them up in parallel.

I have a heatkiller 295 block coming, but there seems to be a bit of a shortage of those at the moment as both PPC and Sidewinders are out of stock.

[SteveRo]

im using EK blocks on my 295s, temps are good, the only drawback for me is the internal design wont let me hook them up in parallel.

I have a heatkiller 295 block coming, but there seems to be a bit of a shortage of those at the moment as both PPC and Sidewinders are out of stock.

In series, do you see much of a temp delta between the two cards?

[JackOfAll]

im using EK blocks on my 295s, temps are good, the only drawback for me is the internal design wont let me hook them up in parallel.

That's my only gripe with the EK block. With back-to-back cards, there is no room to do anything but series. Parallel would be nice. ;)

[JackOfAll]

In series, do you see much of a temp delta between the two cards?

I'm not the original poster, but have a pair of cards with EK blocks in series. I think my GPU temps are a little closer than his. Typically 1-2 deg C between GPU's.

Currently all GPU's are folding the same type of WU. Temps are below.....



Sun May 24 13:10:19 BST 2009
Attribute 'GPUCoreTemp' (c7super:0[gpu:0]): 56.
Attribute 'GPUCoreTemp' (c7super:0[gpu:1]): 57.
Attribute 'GPUCoreTemp' (c7super:0[gpu:2]): 56.
Attribute 'GPUCoreTemp' (c7super:0[gpu:3]): 56.


PS. The temps above are with the cards overclocked to 720/1548/1080 @ 1.05V, from the default 576/1242/999 @ 1.03V.

[SteveRo]

I'm not the original poster, but have a pair of cards with EK blocks in series. I think my GPU temps are a little closer than his. Typically 1-2 deg C between GPU's.

Currently all GPU's are folding the same type of WU. Temps are below.....



Sun May 24 13:10:19 BST 2009
Attribute 'GPUCoreTemp' (c7super:0[gpu:0]): 56.
Attribute 'GPUCoreTemp' (c7super:0[gpu:1]): 57.
Attribute 'GPUCoreTemp' (c7super:0[gpu:2]): 56.
Attribute 'GPUCoreTemp' (c7super:0[gpu:3]): 56.


PS. The temps above are with the cards overclocked to 720/1548/1080 @ 1.05V, from the default 576/1242/999 @ 1.03V.

Is this with the cards in series?

[JackOfAll]

Is this with the cards in series?

Yes, it is.

[shazza]

Not to derail this thread into another huge series vs parallel debate, but admit I'm confused. While we've seen data that shows GPUs will run fine in parallel, I don't think it's been proven definitively that one way is better than the other. Series seems to work just fine. (running 3 x 285s in series with EK blocks, and I see at most 1 degree difference between the cards - and that's a fairly random 1 degree, so is probably within sensor/measurement error).

[SteveRo]

Yes, it is.

looks pretty even to me!

[DarthBeavis]

Not to derail this thread into another huge series vs parallel debate, but admit I'm confused. While we've seen data that shows GPUs will run fine in parallel, I don't think it's been proven definitively that one way is better than the other. Series seems to work just fine. (running 3 x 285s in series with EK blocks, and I see at most 1 degree difference between the cards - and that's a fairly random 1 degree, so is probably within sensor/measurement error).

I agree. I say do what is most convenient although from my experience I will choose series first if possible.

[b@llz0r]

lol... my 295s have a 5degree core difference on air!

I only have one ek block installed at the moment because I am trying to get to the bottom of this temperature difference first.

Series or parallel both work fine, but you physically cant hook the eks up parallel due to the flow paths inside the block... both ports on the one side feed into a common chamber, then shoot off to the gpus in parallel, then collect in a common chamber at the other side and finally out either of the ports on the other side.

I had planned to do parallel in my loop due to placement of my rad and pump. So ill see how the HK does.

[JackOfAll]

Not to derail this thread into another huge series vs parallel debate, but admit I'm confused. While we've seen data that shows GPUs will run fine in parallel, I don't think it's been proven definitively that one way is better than the other. Series seems to work just fine. (running 3 x 285s in series with EK blocks, and I see at most 1 degree difference between the cards - and that's a fairly random 1 degree, so is probably within sensor/measurement error).

Right, and my use case is fairly esoteric, but I doubt with 4x GTX295 in a single mb, in series, (which would be the only way of doing it with 4x back-to-back cards and the EK blocks due to the lack of space between cards and the block design), the temp of the 8th GPU would be within a degree or two of the 1st. ;)

Shazza, I understand what you're saying and in general I'd agree with you. I'm waiting to receive an aqua GTX295 block on Tuesday (with the vertical ports), at which point I'll make a decison on purchasing another 3 of them. With 3 ports per block, I'll have the flexibility to try several ideas, series or parallel. I have an idea in my head - res -> pump -> 3x120 rad -> parallel card 1 / card 2 -> pump -> 3x120 rad -> parallel card 3 / card 4 -> res. Actually, I've got several ideas that I'd like to try. I'd like to end up with a single loop for the 4x GTX295 even if it means using more than 1 rad/pump in that loop.

[SteveRo]

Right, and my use case is fairly esoteric, but I doubt with 4x GTX295 in a single mb, in series, (which would be the only way of doing it with 4x back-to-back cards and the EK blocks due to the lack of space between cards and the block design), the temp of the 8th GPU would be within a degree or two of the 1st. ;)

Shazza, I understand what you're saying and in general I'd agree with you. I'm waiting to receive an aqua GTX295 block on Tuesday (with the vertical ports), at which point I'll make a decison on purchasing another 3 of them. With 3 ports per block, I'll have the flexibility to try several ideas, series or parallel. I have an idea in my head - res -> pump -> 3x120 rad -> parallel card 1 / card 2 -> pump -> 3x120 rad -> parallel card 3 / card 4 -> res. Actually, I've got several ideas that I'd like to try. I'd like to end up with a single loop for the 4x GTX295 even if it means using more than 1 rad/pump in that loop.

Make sure you report back on how you like the aqua - having options that enable tweaking is always a good thing!

[DarthBeavis]

If you want to do sub-ambient why play with CoolIt stuff? Go straight to phase or cascade. For the GPUS setup a water-chiller. One loop would work then ;)

[SteveRo]

If you want to do sub-ambient why play with CoolIt stuff? Go straight to phase or cascade. For the GPUS setup a water-chiller. One loop would work then ;)

What phase cooler would you recommend for i7 965?
If I was to go phase for the cpu and chillers for the vc's - what phase cooler would you recommend?

[JackOfAll]

For the GPUS setup a water-chiller. One loop would work then ;)

That's an option, and feel free to shoot me down, but isn't the compressor going to generate rather a lot more than low-level fan noise?

[SteveRo]

That's an option, and feel free to shoot me down, but isn't the compressor going to generate rather a lot more than low-level fan noise?

For me - moderate noise is not a problem, I have everything in a closet, see my pics in the first post. I have a wall between me and my machines. I wouldn't want 2xGTX295 with fans blowing full blast ALL the time, that I do hear.

[DarthBeavis]

What phase cooler would you recommend for i7 965?
If I was to go phase for the cpu and chillers for the vc's - what phase cooler would you recommend?

you need a custom unit. i have one but i have not tested it on an i7 yet.

[JackOfAll]

For me - moderate noise is not a problem, I have everything in a closet, see my pics in the first post. I have a wall between me and my machines.

Fair enough.


I wouldn't want 2xGTX295 with fans blowing full blast ALL the time, that I do hear.

That's not what I meant. I was referring to fan noise of 3x120mm fans mounted on a passive rad - the cards water-cooled, rather than the stock fans on the cards. I was suggesting an active water-cooled solution with a chiller (and compressor) is going to be somewhat noisier than 3x120mm fans fitted to a passive rad.

[NaeKuh]

there is 3 ways to get a chiller.

1. bong cooler which brings you slightly below ambient.
2. TEC
3. Phase.

The last 2 are true chillers, meaning they require work to take work out of the system.
Problem with chilllers is efficiency. The average chiller can pull more wattage then a b3 kentsfield on load, so u'll need to factor power cost.

TEC's are uber inefficient unless you can find a sweet envelope. I am still in the middle of testing TEC's and now have dumped all my research over to Skinnnee to play with further.

TEC's have been around for a long time, but there still new to our hobby. (meaning not enough venturing was done on TEC's + water).

I feel if u have good quantity of powerful TEC's on a T-stat and regulate on and off cycles on a TEC, its possible to get more efficient then a phase chiller.

It is also possible to pwm a TEC. (err Pulse width modulation) not PAWN as it defeat.

[DarthBeavis]

Did see a review today http://www.bjorn3d.com/read.php?cID=1562&pageID=6834

If you might want a phase unit PM me

[SteveRo]

Did see a review today http://www.bjorn3d.com/read.php?cID=1562&pageID=6834

If you might want a phase unit PM me

I left you pm.
Back to the vc blocks - I want best performance - however - is EK the only provider of acrylic blocks - I like the bling!
Correction - looks like koolance aso has the acrylic center.
what are the advantages of EK over koolance and vice verse?

[SteveRo]

Fair enough.



That's not what I meant. I was referring to fan noise of 3x120mm fans mounted on a passive rad - the cards water-cooled, rather than the stock fans on the cards. I was suggesting an active water-cooled solution with a chiller (and compressor) is going to be somewhat noisier than 3x120mm fans fitted to a passive rad.

Yes, I am planning to set up active cooling from the get-go.
I have two boreas - and these do make some noise when running at full blast - not as bad as one 9800GX2 at full blast though.

[rambler358]

I'm using Koolance blocks on mine. 1/2" Tygon tubing with Koolance compression fittings:

http://img.photobucket.com/albums/v406/Rambler358/Misc/PC/i7-X58/40-tms_installed.jpg

I opted for the Koolance blocks, as I've had other Koolance blocks on previous GPUs and they have always performed well. Running 3DMark Vantage, GPU temps never get above 49*C.

[DarthBeavis]

I know the guys from Danger Den and Koolance and all are cool people and they also make good products. I would recommend either highly.

[DdotRoq]

I have Koolance and absolutely love it. I reccomend it.

[SteveRo]

I'm using Koolance blocks on mine. 1/2" Tygon tubing with Koolance compression fittings:




I opted for the Koolance blocks, as I've had other Koolance blocks on previous GPUs and they have always performed well. Running 3DMark Vantage, GPU temps never get above 49*C.

Wow - beautiful work!
I think I'm leaning towards the Koolance blocks.
What did you use for a connector between the blocks – can you send me a link?

[rambler358]

Wow - beautiful work!
Thanks! :)

I think I'm leaning towards the Koolance blocks.
What did you use for a connector between the blocks – can you send me a link?
Sure, this (http://www.evga.com/products/moreInfo.asp?pn=203-EV-1128-01&family=Accessories - Hardware) is what I used.

http://www.evga.com/PRODUCTS/IMAGES/GALLERY/203-EV-1128-01_MD_1.jpg

[SteveRo]

Thanks! :)

Sure, this (http://www.evga.com/products/moreInfo.asp?pn=203-EV-1128-01&family=Accessories - Hardware) is what I used.

http://www.evga.com/PRODUCTS/IMAGES/GALLERY/203-EV-1128-01_MD_1.jpg

Excellent - it looks like both pieces of h/w come together as one purchase?