Crossfire 4870's w/AC Accels

modoheo

Member
May 28, 2008
187
0
0
I'm interested in the 4870, but would like to keep the heat and noise to a minimum. I have an Asus Rampage X48 board, and I'm just curious if anyone knows whether two 4870's w/ the AC Accels1 Rev 2 aftermarket VGA cooler attached to each would fit in a crossfire configuration, or is the cooler large enough to preclude that possibility? The cooler is this one:
http://www.newegg.com/Product/...x?Item=N82E16835186016

If anyone even knows the width of a single 4870 w/ the above cooler attached, that would be helpful, b/c I could then do the measurements on my mobo myself to see if it'd be doable.
 

chizow

Diamond Member
Jun 26, 2001
9,537
2
0
It will fit, there's folks here that did Accelero mods with the 4850. One thing you will have to do though is squeeze the CF bridge through the fins or cut them in that spot.

Why get 4870CF now though? If you waited this long you should probably wait for the 4870X2 which will have a cheaper price tag and also have 1GB of frame buffer per GPU and 2GB total.
 

modoheo

Member
May 28, 2008
187
0
0
The only reason I'd consider going 4870 crossfire rather than waiting for a 4870X2 is b/c of heat and noise. I don't think it's possible to reduce the heat/noise on the X2 like it would be with two 4870's crossfired with two accelero's, would it? Plus, I don't think the extra RAM on the X2 makes a lot of difference for gaming, and if benchmarks eventually suggest otherwise, I hear the 4870 1 gig version will likely be released soon.
 

AmberClad

Diamond Member
Jul 23, 2005
4,914
0
0
I guess it's possible in theory. The thing to keep in mind is that a fanless Accelero'd card only needs two slots (I wouldn't recommend going fanless on a 4870...). Using a Turbo Module on it will increase it to three slots, and using standard case fans will increase it to four slots.

So judging from the layout of the Rampage Formula, I guess you could do it with Acceleros + Turbo Modules if you really wanted to. And you'd have one PCI slot free for a sound card or something.

But yeah, as chizow alluded to, a 4870X2 seems like a far less cumbersome and awkward solution.
 

chizow

Diamond Member
Jun 26, 2001
9,537
2
0
Originally posted by: modoheo
The only reason I'd consider going 4870 crossfire rather than waiting for a 4870X2 is b/c of heat and noise. I don't think it's possible to reduce the heat/noise on the X2 like it would be with two 4870's crossfired with two accelero's, would it? Plus, I don't think the extra RAM on the X2 makes a lot of difference for gaming, and if benchmarks eventually suggest otherwise, I hear the 4870 1 gig version will likely be released soon.
Well whether 1GB matters or not certainly depends what resolution you'll be gaming at and whether you hope to use a lot of AA. Here's a few examples where lack of frame buffer is causing problems with high levels of AA enabled. It could certainly be problem fixed by a driver update but still an issue best avoided if possible, imo.

You're probably right though about the cooling on the X2 vs. CF. It should be much easier to cool the CF set-up with custom coolers. If you're not in a huge hurry to upgrade, I would probably wait as both the 4870X2 and 1GB 4870 should release around the same time in 2 weeks or so. Personally I think both may offer enough benefit over the current 512MB version to make it worthwhile to wait for thorough reviews.
 

chizow

Diamond Member
Jun 26, 2001
9,537
2
0
Originally posted by: AmberClad
But yeah, as chizow alluded to, a 4870X2 seems like a far less cumbersome and awkward solution.
Yep exactly, but it sounds like he's really concerned about cooling. Thing is though, putting Accelero + the fan kit is going to run another $30-40 each to the price so $60-80 total. That's on top of the premium for going 4870CF ($520-600) compared to the 4870X2 which is supposed to be $499.

 

modoheo

Member
May 28, 2008
187
0
0
Thanks for all the feedback.

Cooling concerns me, but I'm even more sensitive to noise. My hope was to set up the configuration I asked about without additional fans - currently my case (Cosmos 1000) has good airflow with a 120mm fan pumping cool air in from the bottom and 2X120mm fans blowing it out the top (plus another 120mm rear fan), so theoretically my hope was there should be enough airflow bottom-to-top passing over those two accelero's to keep the 4870's cool. I can afford the premium which I'm happy to pay for a lot less noise and heat if it seems to be doable. Chizow- how difficult is it to route the crossfire link threw the fins without cutting?
 

AmberClad

Diamond Member
Jul 23, 2005
4,914
0
0
I've got a similar case fan loadout -- 120mm intake fan, 2x120mm top fans, 120 rear fan. Again, I wouldn't use my Accelero fanless. There's going to be a lot of heat trapped between the card and the heatsink, and I don't think the VRMs and memory modules are going to be adequately cooled.
 

Elcs

Diamond Member
Apr 27, 2002
6,278
6
81
Originally posted by: AmberClad
The thing to keep in mind is that a fanless Accelero'd card only needs two slots (I wouldn't recommend going fanless on a 4870...).

But yeah, as chizow alluded to, a 4870X2 seems like a far less cumbersome and awkward solution.
My HD4870 can be run fanless with my Thermalright HR-03 GT. I still get under 80C at gaming load (not Furmark load0 after 1 hours worth, actually around 75C. I dont run fanless because my turbo module is silent and my extremely basic modding works wonders on dropping the temps to below 50C idle.

In general terms, I agree. An HD4870 should not be run fanless if at all possible.

I also agree with chizow's statement and AmberClad's agreement with chizow's statement. An HD4870x2 would be a cleaner solution, possibly cheaper and undoubtedly they will bring out a nice new cooler for it.
 

chizow

Diamond Member
Jun 26, 2001
9,537
2
0
Originally posted by: modoheo
Thanks for all the feedback.

Cooling concerns me, but I'm even more sensitive to noise. My hope was to set up the configuration I asked about without additional fans - currently my case (Cosmos 1000) has good airflow with a 120mm fan pumping cool air in from the bottom and 2X120mm fans blowing it out the top (plus another 120mm rear fan), so theoretically my hope was there should be enough airflow bottom-to-top passing over those two accelero's to keep the 4870's cool. I can afford the premium which I'm happy to pay for a lot less noise and heat if it seems to be doable. Chizow- how difficult is it to route the crossfire link threw the fins without cutting?
Accelero S1 mounted on a 4850

Near the end you can see where the CrossFire bridge was squeezed through the fins. It looks like you just need to push them outwards to work the bridge through. Just be careful as those fins like any machined metal can be very very sharp.

Like Amber said, I don't know if its a good idea to run 4870s on passive cooling, especially if you don't have at least some local fans pushing/exhausting hot air. I know there are reports of people running 4850 passively but the 4870s are basically overclocked variants that draw more power and have more complicated VRM modules. If you were dead set on going passive, you may want to look at some slot blowers maybe to exit some of that hot air from the expansion slots instead of relying on your rear and top blowers near your CPU.

Personally I'm a big fan of side-mount fans for cooling video cards; I know a lot of people say they're pointless with good case airflow but I've found that to be grossly inaccurate. I don't know how much additional cooling you can manage in your Cosmos 1000, but 1 x 120mm intake seems a bit light to me. Generally adding more fans doesn't bother me much, as long as they're the same RPM and dB rating. There's a little more turbulence but its not noticeably louder or more bothersome. What card and what kind of temps are you getting now?
 

modoheo

Member
May 28, 2008
187
0
0
FWIW, I forgot to mention that I also have two other 120mm fans in the case, one sitting on top of the HD cage blowing air diagonally up toward the top, and another on a Xigmatek 1283 CPU cooler oriented so it also blows upward toward the two top exhaust fans. Although there's only one fan "pulling" on the bottom of the case, there's 5 others "pushing" air out of the case. Theoretically there should be quite an airflow bottom-to-top. The Cosmos also comes with a VGA air intake duct (that I'm not currently using) that's designed to route air pulled in by the fans from an intake in the rear of the case right across the GPU's.

Right now I have a 8800GTX, which i just rechecked using pc wizard and everest and seems to be running well within spec on stock cooling - 61C at idle and 79C full load (right after running 3dMark06). What are the recommended temps for the 4870's? I might end up cautiously trying it "passively" with the accelero and the fan setup in my case, adding the turbo fans as needed.

Elcs - what sort of cooler do you envision for the X2? I expect the stock one to be a noisy, hot beast.

BTW, I'm assuming my Corsair 750W PSU is beefy enough for such a crossfire setup.
 

octopus41092

Golden Member
Feb 23, 2008
1,839
0
76
Originally posted by: AmberClad
I guess it's possible in theory. The thing to keep in mind is that a fanless Accelero'd card only needs two slots (I wouldn't recommend going fanless on a 4870...). Using a Turbo Module on it will increase it to three slots, and using standard case fans will increase it to four slots.

So judging from the layout of the Rampage Formula, I guess you could do it with Acceleros + Turbo Modules if you really wanted to. And you'd have one PCI slot free for a sound card or something.

But yeah, as chizow alluded to, a 4870X2 seems like a far less cumbersome and awkward solution.
I'm using standard 120mm case fan and it only takes 3. But that's on an HD4850 I'm not sure about the HD4870
 

AmberClad

Diamond Member
Jul 23, 2005
4,914
0
0
Hmm, in my case I'm pretty certain it's four total slots (excuse my bad webcam). I'm counting the card itself as one of the slots. I have nothing in slot 1, the card is in slots 2-5, and I have a PCI card in both slots 6 and 7. Are you saying I could use another card in slot 5? Doesn't look like it to me :p.

Are you using those standard 120mm by 25mm deep fans? Or compact fans like the slim Yates?
 
Thread starter Similar threads Forum Replies Date
X Graphics Cards 16

ASK THE COMMUNITY