Enough Radiator for SLI?

[weescott]

I have been thinking about watercooling 2 x GTX XXX cards with a single PA120.1 and a Yate Loon fan. I'm looking at using some Silverprop blocks (If I can find any). The case cooling will be enough for naked ram overclocked. I don't see the need for full cover blocks. They are a total waste of time IMO.

Just wonder what people opinions of this set up are, and what limitations (if any) it would have.

[pie_uk]

If you have a 32-bit version of Windows (which, let’s face it, most of us do) then the devices that require memory-mapped access must reside inside 4GB (see here for more information.)

So, if you have two 768MB GeForce 8800 GTX cards in SLI, then Windows has to set aside 1,536MB of this 4GB space, which means the maximum amount of memory your PC will be able to see is 2,560MB – just 2.5GB. And it will be 2.5GB whether you have 3GB, 4GB or 8GB of RAM installed.

Now look ahead to Quad CrossFire, which could mean, potentially, four 512MB (or larger) graphics cards. This would limit a 32-bit PC to 2GB (or less) of usable RAM, regardless of what is installed. Now imagine three 768MB 8800 GTX cards – that will only leave 1.7GB of RAM!

Clearly, multiple high-end graphics cards is only really feasible in a 64-bit OS, where the 4GB limit obviously doesn’t apply, but we’re still some way off 64-bit being the standard on desktop PCs.

So the moral of the story is, if you have a 32-bit OS, stick to a single graphics card or you could lose your memory…

quote from cpc

why are full cover blocks a waste of time?

[weescott]

I was asking about the merits of watercooling 2 overclocked GTX's with a PA120.1. That's why I posted in the watercooling section. I have Vista 64 installed but that has nothing to do with what I asked. I know the limits of RAM on 32 bit OS's. I have 2 gig of ram installed and I'm thinking about upgrading to 4 gig. But that's for another discusion.

IMO full cover blocks are a waste of time because ram doesn't see any substantial gain from watercooling it. Decent air flow is enough IMO.

Also, one can spend double the amount on full cover blocks to have them rendered useless when new cards come out. What would you rather replace? A maze 4 or a full cover block?


I am open to debate so if you can prove my philosophy wrong then go ahead.

:)

[Pete]

OMG PIE_UK slap slap!

GDDR ram is what was ment as this was about GFX cooling.

Some Swiftech heatsinks off Tom Scotty will do you nicely.

It's more for astheitc than anything and FC block are OTT and so last year

[jabski]

not sure a PA120.1 will let you overclock on 2x GTX. What sort of temps will you be getting. Maybe a PA120.3 would be better :)

[weescott]

Yes a PA120.3 would be "better" and certainly cooler. But how much would it better my clocks over a PA120.1?

[jabski]

Marci would be the man to answer that question. I doubt you would be able to overclock much on a 120.1 maybe not even atall

[lowfat]

I highly doubt that will be a big enough radiator, unless you are going to use a 100+ CFM fan. I would suggest at least a dual radiator.

[pie_uk]

oops, sorry weescot :)

just i didn't know that and thought id share it

120.2 would be fine. i think you will be exceeded the cooling capacity of a single tbh

[Mekrel]

at 1.5GPM with a 41dB panaflow (http://www.panasonic.com/industrial/appliance/pdf/fba12g.pdf) fan, the PA120.1 can dissipate 200watts of heat.

All you need to find out is how much heat the core only gives out if you're only actively watercooling that.

I'm sure Gabe in a thread about the Stealth mentions a figure for the core only.

[weescott]

I'm sure Gabe in a thread about the Stealth mentions a figure for the core only.

Yes. 100w was mentioned. 189w was Nvidia's figures I think.

200w capacity for 200w of heat, but that I guess will be with a high CFM fan. Add to the fact that these cards will be overclocked and temperatures are never going to be great. But, it's still going to be better than stock cooling for temperatures and noise. That's my theory anyway.

[lazy]

if your going to be running he fans @ or around 100cfm then it will be too loud for comfort

[weescott]

I used to run a Delta. I know what noise is! lol. But you do draw a valid point of the rads capacity with a managable yate loon fan.

[ChiLlInGw/H2o]

I would buy a PA 120.2...the price difference between the single and double isnt that much . Later if you keep anything long enough you can still use the same rad. If the next generation cards are a little hotter then you will have to buy another rad anyways...so get the double now and save you some money later.
As far as the full coverage WB's I dont use one and all is good. BUT make sure you put some type of heatsinks on EVERYTHING on the card that needs it. I think you can buy a kit for that which cost about 40 US dollars. I personally just cut some old copper heatsinks I had up and used those