290X Crossfire with Corsair HG10; top card running HOT

[NightHawkIX]

I just got a second R9 290X with a HG10-A1/H60 AIO to set up crossfire. My original 290X is on a HG10-A1 with a H80i. Both H60 and H80i are in push/pull configuration with 2x Cougar Vortex 120mm fans (intake of case).

Card 1: 290X / H60
Card 2: 290X / H80i

What I'm noticing is a large temperature difference between card 1 and card 2.

Card 1 Idle: 42
Card 2 Idle: 37
Card 1 Load: 76
Card 2 Load: 70

Is the difference a result of the thicker rad on the H80 vs H60? Or is there something else going on? I wouldn't think the thicker rad would make a difference in idle temps.

I checked the seating of both cooling blocks and they're both secure with the same thermal compound application.

Edit: Card1's VRM 1/2 temps are also higher:

Card 1 Idle: 49/49
Card 2 Idle: 41/41
Card 1 Load: 110/64
Card 2 Load: 81/60

Is the 1st (top) card's fan helping to cool down the 2nd card?

Catalyst 16.8.2
GPU Core Clock: 1066 MHz, Memory Clock: 1266 MHz
Core voltage +25 mV

 

[weberdarren97]

There are multiple things here that are parts of the causes of the temperature difference.

The first being that the thicker radiator cools more efficiently.

The second being that heat from the back (top) of the PCB on the bottom card would be rising and running into the top card... Causing a difference in VRM temps.

The third would be that it looks like the HG 10 on the bottom card is seated flatter than it is on the top card... But this could just be the camera angle.

All that said... Your temps are acceptable. I don't really think anything needs changed.

 

[NightHawkIX]

Thanks!

reason I ask is because in several games: BF4, Crysis 3, Witcher 3, and DA:I, I'm getting much lower than expected frame rates.

Playing at 3440x1440 (LG Freesync monitor), trying to used maxed out settings.

BF4 is giving me 40-50FPS, Crysis 3 is averaging 35, Witcher 3 is averaging 40, and DA:I is averaging 50 but with lot of stutter.

I was concerned my top card was thermal throttling or something...

I've played around with the Crossfire settings from default, to AMD profiles. Turning on/off frame pacing, etc with no luck :/

 

[weberdarren97]

The best setting for Crossfire X is AFR Friendly.

Also, most of the games you mentioned are not Crossfire optimized.

Your card is not thermal throttling.

However, they may be throttling because of the power limit. Have you changed the power limit? I would raise it by 5% from default.

 

[NightHawkIX]

Looks like most of these games, if I turn off AA, it drastically improves performance.

Are crossfire profiles just incompatible with AA?

Also looks like I'll try to reseat card 1's HG10, VRM1 hit 127 after 30 minutes of Crysis 3 (card 2 VRM1 was 95)

 

[weberdarren97]

Looks like most of these games, if I turn off AA, it drastically improves performance.

Are crossfire profiles just incompatible with AA?

Also looks like I'll try to reseat card 1's HG10, VRM1 hit 127 after 30 minutes of Crysis 3 (card 2 VRM1 was 95)

Please make sure that AA is turned off in Catalyst Control Center. When using Crossfire, that should be set to Application Specific and you should use the in-game AA settings.

Here's the thing, AA makes a GPU "take a closer look" at what it's doing... It makes it render more samples, which can smooth edges and make non-straight lines look more realistic, but it puts an increased load on the GPU.

Is Crossfire incompatible with AA? No. But, since you have two cards, the effective sluggishness of adding AA is twice what it would be if you only had one card.

Do you have any heatsinks on the VRMs or are you just blowing air across them? You can get small heatsinks that would likely fit under the HG 10's shroud.

 

[NightHawkIX]

Right now I just have the fan blowing over the HG10, no additional heatsinks taped on.

I think I'm choking my case with hot air by putting the rads of the H80i/H60 on the intake. I took off the front panel of my case (NZXT H440) and noticed a 4 degree drop in idle temps for card 1. About a 10 degree drop under load.

I might move the H60 rad to exhaust, and have an extra fan just working intake to blow cold air over the GPUs.

 

[weberdarren97]

I might move the H60 rad to exhaust, and have an extra fan just working intake to blow cold air over the GPUs.

I second that idea.

I would also get some small little heatsinks for the VRMs.

Wait a minute... I just realized an issue with my idea of adding heatsinks. The Corsair HG 10's shroud prevents the adding of heatsinks to the VRMs.

You could cut the shroud at the highlighted areas in this image, but IDK if you've ever modded before and I don't want to force you to do something that you're not comfortable doing.

If you're going to add heatsinks, I recommend these.

 

[NightHawkIX]

Moving the H80 to exhaust dropped the VRM1 temps of Card 1 by about 10 degrees.

One of the cards is drawing more power than the other despite being both 290X references at the same clock (1066Mhz, +10% power draw). 250W vs 198W

 

[weberdarren97]

No two cards are the same. You also have to consider that those cards will throttle the amount of power they draw based on core temperature.