HD4870, Accelero Twin Turbo & Temperature ...

[sgegmund]

Hello,

I have a Sapphire HD4870 (the latest one, with the black fan case and the fan in the middle, a non-reference layout), and I had several problems with it unmodified (750/900 GPU/MEM stock):

1. It worked ok with stock values and stock cooler, even if a VPU recover kicked in sometimes. As HD4870 is supposedly easily over clocked, I started playing with CCC a little bit. I couldn't reach anything amazing, even with fan speed at 100% (see below), 780/960 was almost the best I could get without crashes every 10 or 20 minutes.

2. The fan noise (from 60% to 100% speed) is just unbearable unless you play with loud sound and earplugs, but that would mean to become deaf really fast... 3 intake 120mm fans, 3 exhaust 120mm fans, CPU fan and PS fan, and this single 80mm fan is of course making more noise than all the others together.

So, I basically had a not so bad HD4870 working ok at stock values, that I could over clock just a little bit, with the problem of the fan noise.

Needless to say I was not really satisfied, as I have drooled on great over clocking values that you can find on different sites, or even stock values from some factory OC'ed cards.

Soooooooo, as the temperature values from GPU-Z were a little bit high, I decided to get an after market cooler. Arctic-Cooling Accelero Twin Turbo.

Installation : The main GPU heatsink, and the RAM heatsinks are really obvious to install, but it wasn't really clear where to put the VRM ones (remember, non-reference layout). I ended up using my dremmel (cutting tool) on the 4 VRM heatsink included to cover all the remaining places on the card.

1st Test : Awful. All temperatures raised, and got a VPU recover after only 10 seconds of small GPU stress. That was with the pre-applied thermal patch on the main heatsink.

2nd Test : Removed everything again, cleaned correctly both heatsink and GPU (asaka cleaning stuff with 2 different products). Applied Arctic-Cooling MX-2 (ceramic, non conductive) correctly, and I finally managed to let my card run for more than 1 hour with 750/1100 values. The DISPIO T° is not going over 68°C, the SHADERCORE T° is reaching 75°C and the MEMIO is reaching 92°C after one hour. Idle temperature are DISPIO/SHADERCORE/MEMIO = 40/45/55

I'm quite glad right now even though I didn't have time to test GPU OC yet.

But, I would still like to get any opinion on the temperatures (especially MEMIO). If I understand it right, the MEMIO sensor is on one corner of the GPU (can't remember which one). So does a high T° mean the RAM is too hot(the RAM heatsinks are not even hot at all) or does it mean that the main Heatsink is not correctly applied on the GPU ?

Thank you for any answer/advice.

 

[nafets]

A greatly disproportionate spread between MEMIO and the other two temps is a good sign the GPU heatsink isn't seated flush against the GPU core. Your spread isn't too bad, but personally, I'd go for another re-install of the Accelero and really take your time mounting/screwing it in evenly.

It may be "easy" to overclock an HD4870, but there is nothing that says you will achieve great results. Depending on how tight Sapphire has been recently with their chip binning, you may just be stuck with a dud RV770 core that doesn't want to run faster. There will always be a good amount of leeway on the memory though, as the majority of the GDDR5 chips on HD4870s are spec'ed to run at 1000MHz. But gains from OC'ing the memory aren't as noticable as with a faster clocked GPU core.

Good luck...

 

[Darknova]

This really surprises me. I have the same card you do, and the fan rarely kicks in, all my temps are below 55'C 99% of the time, even playing graphically demanding games. I found the stock cooler to be really good (better than the Accelero S1 and Scythe Musashi coolers I'd used on my previous 4870).

Like nafets said it's possible you got a dud core, but have you tried reseating the original cooler with better TIM (IE MX-2) ?

 

[sgegmund]

First of all, thank you all for your answers. As suggested, I went for a reinstallation of the main heatsink.

1st try : complete cleaning (asaka cleaning x 2), reapplying AC-MX2 evenly, resetting the heatsink. No dice, GPU-Z temps even raised to almost 70°C idle.

2nd try : instead of completely cleaning the thermal paste, I used a brush to evenly spread the thermal MX2 (as I've seen Zalman using a brush on their thermal paste). Re re re re re screw, re re re re re set the card and ... well ... my idle temperatures are now 39/45/40
As I couldn't believe the results, I tried a full load for about an hour, the highest temperature reached was 67°C on the MEMIO, 59°C on DISPIO and 63°C on SHADERCORE. And that is with the fans set to 75% speed.

So to everyone having temperature issues with their aftermarket cooler, the most important part is the correct contact between main heatsink and GPU ! Use Good thermal paste, apply it evenly in a thin layer (I used a brush) and make sure the heatsink is evenly attached to the card.

I didn't try OCing yet, but the temperature issue is now gone, so I can test different OC values and be sure that it won't be a temperature problem if it doesn't work

 

[OnBoard]

That's quite weird. I had no temp issues with my TwinTurbo with it's stock applied paste, nor did I with Accelero Xtreme GTX 280 stock application. Even mounted the latter 2 times with the same paste and still worked great.

 

[nafets]

Well whatever the initial problem was, it's good to see it's resolved and your temps are under control.

Great job Sgeg! Now onto the OC'ing...

 

[Polarman]

Funny, you're using the latest GPU-Z bit i don't see your VDDC temps?

 

[Darknova]

Funny, you're using the latest GPU-Z bit i don't see your VDDC temps?

These Sapphire cards don't have the sensors on them, it uses MOSFETs instead of VRMs.

 

[AltecV1]

i wanted do buy the same cooler for my 4850 but they where out of stock and i had do buy accelero s1

 

[sgegmund]

Funny, you're using the latest GPU-Z bit i don't see your VDDC temps?

Yes, as mentionned above, it is not a reference layout. I had to use a cutting tool to put heatsinks (those made for VRMs on reference cards) on all required components and I also had to use the stock VRM (or in this case MOSFET) heatsink. I removed the thermal band, and applied mx-2 on the chips. It seems to work nicely.

Orange are RAM heat sinks, thermal tape.
Green is MOSFET stock Heatsink, removed thermal band and applied MX-2 on the chips.
Blue are VRM heat sinks, cut to fit the remaining components (some may not be useful, but as I wasn't sure, I still put them on ).

It's also funny to see that the main stock heat sink is used to cool RAM with huge thermal pads that look like thermal insulators rather than thermal conductors (Good pictures of the stock stuff can be found here. The page is in french though.).

 

[Darknova]

Thanks for that information sgegmund, I didn't want to remove the heatsink because I couldn't work out which MOSFETs were which heh.

Now I'm going to replace the thermal paste