6950 Twin Frozr III vs reference for crossfire

I'm looking to upgrade to 6950 crossfire and debating whether to go with two reference cards or two Twin Frozr III's. The main concern between the two is heat/noise rather than performance; my mobo has no slots between the video slots so the cards will be right up against each other. My house has no AC & it gets toasty warm in the summertime so I'm looking for the configuration that will run the coolest.

Trying to figure out whether the Twin Frozr cooler will help or hurt in this situation.

Case is a Silverstone FT02 so there is a 180mm fan that will be blowing air right into the bottom of the cards.

Anyone have any experience with crossfire on any of the frozr cards?

EDIT: Gaming on a 30" monitor.

To answer my own question (in case it benefits anyone else) I picked up two Twin Frozr III's and I'm seeing 90c temps / 100% fan on the inside card. So no way these work for crossfire w/o some spacing between the cards.

I'm trying downclocking them now to reference 6950 speeds to see if that helps at all. So far after 5 min in BF2 the inside card is 79c (with the case open). Doesn't look good.

What's your ambient room temp since you don't have AC.

Right now about 68F, (when the cards hit 90c), but in the summer it can get up to 85F or so during the day. No way this setup would take that heat and honestly these cards aren't working well so close together. When the fans spin up to 100% they blow a lot of hot air back into the case (which defeats the cooling of the FT02 which is trying to suck cool air in the bottom and exhaust hot air out the top). Underclocking to reference clocks dropped 2-3c off the temps but that's not enough.

I've got one card in there now and I let it sit in BF2 for a half hour and it topped out at 60c so one card by itself is fine.

My choices at this point are to pick up another mobo or return the cards to the egg and pay a $90 restocking fee.

Ouch. That really sucks.

rangda said:

My choices at this point are to pick up another mobo or return the cards to the egg and pay a $90 restocking fee.

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Buy a larger case with more effective cooling?

Yeah I don't know was pinheaded and didn't think of it right away but moving to a larger case (say HAF 942) that would let me use my 3rd GPU slot (which is slots 7/8 so my FT02 with 7 slots won't let me use it) would solve the problem.

I've seen some pictures of people using case fans to drive air between the cards so I'm going to give that a shot and if temps are still high put everything in a HAF 942 (unless someone can recommend a better high airflow case but that one looks pretty good).

I have tri fire reference 6950 stacked next to each other. They are all unlocked and clocked at 928/1250 @ 1.145v and they never get past around 80-83 on the hottest card of the three. The other usually tops no higher than 80 and 75 respectively.

It was my understanding that vapor chamber used on reference cooler is better than older heat pipes used on frozrs. Not to mention they cheap out without any backplates either. I would usually pass a non reference unless reference models weren't available anywhere.

Someone at work has offered to let me his 5870 so I can try crossfiring it /w my current 5870 (what these 6950's were going to replace) to get some metrics on noise and temps. I think it will help me figure out whether I need a new case and/or reference cards.

I've just built a system with two MSI R6950 Twin Frozr III's and temps are not an issue.
My build it documented in this thread over at anandtech... hope my information helps you in your decision.

i am, however; having trouble getting proper Crossfire scaling in Crysis (original).
i've outlined my issue/benchmark results in a post i just made in this thread.

Saw your thread in the video card section and gave you some Crysis numbers from my cards.

My mobo has 2 slot spacing between the cards yours has 3 so you've got a gap (It actually has a 3rd slot but it's slots 7/8 in a case so it needs an EATX case to use it). The frozr doesn't seem to react well without some room to draw air. And my case is a FT02 which I suspect has less air flow than yours. But it's good to know the cards can give good temps.

At this point I'm trying to figure out what parts to change. I've got a 2nd 5870 on loan so I'm going to try crossfiring my old 5870 /w this one to get some idea how blower style cards react in the case; once I get those numbers I should have a better idea of what to do. If I buy a new case it will most likely be a HAF X which I can buy at my local Micro Center. That should improve airflow substantially. It also has 9 slots so I can space the cards out /w my mobo. I could also buy a new mobo (which is more expensive and more aggravation), ASUS Rampage III Formula for example looks like I could use slots 1/3 and still fit the cards in my 7 slot case. But I hate to buy a $300 X58 mobo this late in the game.

From what I've seen so far with the frozrs when the fans crank up most of the air they push gets dumped into the case, very little ejects out the exhaust. So when the card heats up you're adding a lot of hot air to the case. If temps drop to the low 60's this isn't much of an issue but I'm not entirely comfortable with that so I may swap the cards to reference cards anyway even if I get a new case. The restock fee and the price difference between frozr/reference are about equal so the swap wouldn't cost me much more money if I want to do it.

Just a heads up, be careful with placing the card in the last (lowest) slot. That places the intake fans on the Twin Frozr III extremely close to the bottom of the case, which may starve them.

Fortunately in the Fractal Design XL case there is a panel i was able to remove between the bottom of the mobo compartment and the bottom mounted PSU compartment. By taking this panel out i allowed the GPU mounted in the last slot to breath.

So long as you have adequate air flow through your case i don't think the Frozr III should be an issue. I've got 5 dedicated case fans, 3 intake, 2 exhaust... after playing Crysis for 30 minutes last night (with my CPU OC'd to 4Ghz) neither the gpu temps or cpu temps exceeded 60C.

DrBoss said:

Just a heads up, be careful with placing the card in the last (lowest) slot. That places the intake fans on the Twin Frozr III extremely close to the bottom of the case, which may starve them.

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Of course putting them in adjacent slots starves the first card, which is the problem I have now (fan sounds awful like that BTW).

As I recall the HAF X had a fair amount of room below the bottom slot (it's a 9 slot case so with the card in slots 7/8 you've got at least 1 slot of space there).

i getto modded my 5870's with some folded paper to create a gap between the 2 cards, saw a 10 degree drop when they have a little bit of space, guessing the 69XX series is even worse then my 5870's.

So I have a friend's 5870 & my 5870 in the case:



Did my 15 min sitting at the beginning of BF2 test and temps peaked at 63/56c. That's 27c cooler than the frozers were. I was running my custom fan profile which had the fans at 50/38%. And no hot air in the case at all.

Messed around some in DAO and cards never broke 56c. Turned my fan profile way down cards went up to 65c but were pretty quiet.

I need to mess around a bit more tomorrow but I think I'm going to RMA the frozrs for reference cards.

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That's too close. Either you need to pick another motherboard with more space between PCIex16, or to have your 6950s watercooled before coming summer.

EDIT: sorry i forgot they're Twin Frozr (not reference design?) so water blks may not work on them...


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Wow that's odd. I would also suggest getting a mobo with more slots. Maybe it has to do with the blower style cooler. BTW, let me know if you feel like trading one of those Twin Frozrs for a reference

adoru65535 said:

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That's too close. Either you need to pick another motherboard with more space between PCIex16, or to have your 6950s watercooled before coming summer.

EDIT: sorry i forgot they're Twin Frozr (not reference design?) so water blks may not work on them...


.

Click to expand...

the PCB's and everything on it are identical, just the heatsinks are different.

Did adding case fans help?

Adding 2 80mm fans blowing air down on the cards dropped frozr temps about 5c (peaked @85), but they were still @100% fan and still dumping tons of hot air into the case.

The FT02 really wants all airflow to be from the bottom of the case to the top so the frozrs pushing air all over the place messes up the cooling of the case. As opposed to the reference blower design sucking air in (right by that 180mm intake) and exhausting it out the top which is exactly what the FT02 wants. Comparing my 5870 experiment to reference style 6950's, the unknowns would be that the 6950's are closed off on the bottom while the 5870's are semi-open and I'm not sure if that little gap between the cards you see in the photo will be there with 6950's.

Part of my problem is bad mobo design, as you can see the mobo is giving up 2 slots of space to the right of the video cards which limits card placement in a standard ATX case.

Assuming reference 6950's are anywhere near the 5870 63c/50% fan peak I think I'm fine with the cards adjacent. But the next build will definitely have 3 slot spacing between the video slots. I'd just rather than next build be LGA2011 rather than another X58 mobo.

To add some closure to this thread:

I RMA'ed the frozrs. Replaced them with 2x reference 6950's. The shrouds are definitely larger than the 5870 shroud, they were touching when I installed them. I used the trick of putting a zip tie between the cards to open up a bit of space (install ends up looking pretty similar to my 5870 pic). Ran them for an hour in BF2, peak temps were 66/64c. Case interior is nice and cool, top of my case doubles as a hand warmer.

Kind of interesting that the temps of the two cards are so close.

Glad things turned out well- I've been looking at this case for some time, and with my 30" panel I've decided to trade my GTX570 for an HD6950 2GB for the extra memory and better scaling. Just glad to hear that they run cool in this case, hope that they run quiet too!

IdiotInCharge said:

I've been looking at this case for some time, and with my 30" panel I've decided to trade my GTX570 for an HD6950 2GB for the extra memory and better scaling. Just glad to hear that they run cool in this case, hope that they run quiet too!

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I have a 30" panel as well, 1 6950 might not be enough depending on what games you play (BFBC2, Metro 2033, & Stalker CoP didn't run so hot with my 5870 that the 6950's replaced). Regarding noise I'm running a custom fan profile to get those temps; I've backed it off a bit to where it has the fans around 40% @70c and the hotter card runs 68-70c depending on the game. With the fans running at 40% they are audible but don't bother me at all.

I haven't unlocked anything yet, waiting for the summer heat to see what kind of temps I get before unlocking shaders or pushing the cards at all. For now it's just great to be able to run games /w AA & advanced effects on.

Good feedback, thank you!

I'm sure I'll be able to get along with a single HD6950 2GB- I'm using an HD4870 1GB until my new card arrives later today, and it's still kicking along wonderfully at reduced settings, far better than I'd expected.

The second card will wait for a Sandy Bridge upgrade down the road- my total wishlish right now crests $2,000, so it may take me a little while!