HD 4870 and Accelero S1 problem

rpsgc · Post by **rpsgc** » Fri Nov 28, 2008 8:14 am

Hello,

I just bought a HD4870 and was planning on using my current S1. That was before life screwed me over again, of course

- Accelero's VRM heatsink doesn't fit.
- I tried using the stock cooling's red plate but I can't bloody unscrew it. I only have a small screwdriver and I just can't unscrew those little screws.

So, now what? What am I supposed to do? I hate AC so much right now...

rpsgc · Post by **rpsgc** » Fri Nov 28, 2008 12:52 pm

Nevermind... I made the heatsink fit

It'll have to do for now. I'll try and get a new screw driver to use the stock red plate.

120/133/125Âº C during Furmark is rather high but seeing as I don't usually play Furmark, it's OK I guess. (the last two VRM aren't fully covered by the heatsink, hence why they are hotter).

2 x rthdribl = ~90Âº C not bad.

bonestonne · Post by **bonestonne** » Fri Nov 28, 2008 12:59 pm

133C for anything is too high, you're in a danger zone with that.

how well is the Accelero seated? if it's that high, it can't be seated well at all. if the heatpipes are in the way, maybe a copper shim will solve that to raise the accelero, but you'll need to find longer screws to accommodate the heatsinks new height.

rpsgc · Post by **rpsgc** » Fri Nov 28, 2008 1:02 pm

bonestonne wrote:133C for anything is too high, you're in a danger zone with that.

how well is the Accelero seated? if it's that high, it can't be seated well at all. if the heatpipes are in the way, maybe a copper shim will solve that to raise the accelero, but you'll need to find longer screws to accommodate the heatsinks new height.

I'm talking about the VRMs... the GPU temperature is rather cool @ 60Âº C during Furmark.

krille · Post by **krille** » Sat Nov 29, 2008 1:45 am

I would like to know this too. Is 4870 + Accelero S1 stable without any additional mods? Or are the PWM:s overheating? Having an unstable video card - and ultimately computer - is not a very tempting solution.

rpsgc · Post by **rpsgc** » Sat Nov 29, 2008 1:58 am

krille wrote:I would like to know this too. Is 4870 + Accelero S1 stable without any additional mods? Or are the PWM:s overheating? Having an unstable video card - and ultimately computer - is not a very tempting solution.

I don't know about other people but the Ramsinks that came with the Accelero stayed on just fine. No problem there. And the memory temperature stays at ~63ÂºC during Furmark. Those are fine.

The VRM heatsink though, is not fine. You can either have it tilted sideways and use both screws or just use one screw and zip tie it or whatever. Having it sideways only covers one VRM and the other two are only partially covered. That one gets very hot (~120ÂºC) but still under the temperature limit. The other two get hotter obviously reaching up to 135ÂºC. With a second fan cooling the VRMs I'm sure they'd be cool enough.

Oh and the card isn't unstable at all. At least I didn't notice anything yet. The VRM simply go past the recommended max temperature during Furmark and Furmark alone because while gaming I'm yet to witness temperatures higher than 80ÂºC for the VRM.

I tried 2 sessions of rthdribl and the VRM only reached ~90ÂºC. Perfectly safe.

zikje · Post by **zikje** » Wed Dec 10, 2008 9:46 am

Could you place a picture of this VRM problem with the heatsinks?

blackworx · Post by **blackworx** » Thu Dec 11, 2008 8:26 am

A couple of possible solutions:

1) Cut off the VRM part of the original HSF and screw that back on.

or

2) Get something like these. NB: the title says RAM heatsinks but they are not, they're sized perfectly for 48x0 VRMs and low-profile chokes. I just bought a pack for my 4850's RAM (because I have a Rev1 S1 with the sh*tty RAMsinks that don't stick properly) only to discover this

but if I get nasty VRM temps I'll be using them.

Edit: Manufacturer's page

krille · Post by **krille** » Thu Dec 11, 2008 9:26 am

rpsgc wrote:I don't know about other people but the Ramsinks that came with the Accelero stayed on just fine. No problem there. And the memory temperature stays at ~63ÂºC during Furmark. Those are fine.

The VRM heatsink though, is not fine. You can either have it tilted sideways and use both screws or just use one screw and zip tie it or whatever. Having it sideways only covers one VRM and the other two are only partially covered. That one gets very hot (~120ÂºC) but still under the temperature limit. The other two get hotter obviously reaching up to 135ÂºC. With a second fan cooling the VRMs I'm sure they'd be cool enough.

Oh and the card isn't unstable at all. At least I didn't notice anything yet. The VRM simply go past the recommended max temperature during Furmark and Furmark alone because while gaming I'm yet to witness temperatures higher than 80ÂºC for the VRM.

I tried 2 sessions of rthdribl and the VRM only reached ~90ÂºC. Perfectly safe.

Is that the PowerColor PCS+ HD4870 1GB GDDR5 (AX4870 1GBD5-PPH) you've got (the one stock overclocked to 780/3700 with a non-reference cooler)? Or is it the "vanilla" reference version (750/3600)? (I would guess it's the normal one since your sig doesn't say "PCS".)

If I'm not mistaken, the original 4870 512MB PCS+ was haunted with stability issues. Would you happen to know if these have been fixed with the 1GB version? I'm also interested in how well the Accelero S1 fits on this 4870 1GB PCS+ seeing how it uses a non-reference cooler already. (If the fit is even worse than on a reference card that's definitely bad.)

My retailer has this stock-overclocked 1GB "PCS+" version going for the same price as the reference 1GB one; as long as it's stable and Accelero S1 compatible the "PCS+" would seem to be the best value.

rpsgc · Post by **rpsgc** » Thu Dec 11, 2008 9:34 am

It's the normal version. The PCS+ would be better because it already has heatinks on the memories and VRM modules but it is said to have some problems.

krille · Post by **krille** » Fri Dec 12, 2008 2:04 am

rpsgc wrote:It's the normal version. The PCS+ would be better because it already has heatinks on the memories and VRM modules but it is said to have some problems.

I see. What specifically are these problems you speak of?

As I said, I read some stuff earlier (months ago) about the Powercolor 4870 512MB PCS+ having stability issues. I think Powercolor blamed it on the BIOS (not sure if it was ever fully fixed though). I haven't actually seen anything said in regards to this and the 1GB PCS+ version though.

I did however read some user reviews over at Newegg (read redbarron's posts here). One customer claimed that PowerColor had silently changed (downgraded) the PCB of the Powercolor 4870 1GB PCS+. From initially using the reference high-quality PCB design, PowerColor would now have adopted a new cheaper non-reference one. This, the user continues, has not only decreased overclockability (and thus probably stability) but has also resulted in increased temperatures (possibly even worse if true). Is this what you speak of? I would really like to know whether this is true. Or is the 1GB PCS+ too haunted by what Powercolor claimed to be "BIOS issues"?

As for my purchase decision, I'm not sure what to do here. A stock overclock is nice. I probably wouldn't overclock a reference 4870 1GB myself as I want it to be quiet and stable and then there isn't much room for overclocking on a high-end card. These perfect fit memory and PWM heatsinks you speak would perhaps be even more useful than the OC. But is the price of a possibly second rate PCB really worth it? If there are still BIOS issues I would say definitely not.

What are your thoughts?

zikje · Post by **zikje** » Fri Dec 12, 2008 2:34 am

Don't know about this, but I'll think I'll go for the Club3D one then.

krille · Post by **krille** » Sun Dec 14, 2008 3:50 am

So, should I go with the Powercolor 4870 1GB PCS+ or just a reference one? They're all the same price. Need to know as I should decide today.

If the PCS+ is more compatible with the Accelero S1 then that's great. But is it really and what exactly were the problems with this card?

rpsgc · Post by **rpsgc** » Sun Dec 14, 2008 3:54 am

krille wrote:So, should I go with the Powercolor 4870 1GB PCS+ or just a reference one? They're all the same price. Need to know as I should decide today.

If the PCS+ is more compatible with the Accelero S1 then that's great. But is it really and what exactly were the problems with this card?

FWIW:
http://en.expreview.com/2008/08/23/powe ... check.html

krille · Post by **krille** » Sun Dec 14, 2008 4:04 am

rpsgc wrote:FWIW:
http://en.expreview.com/2008/08/23/powe ... check.html

Isn't that the 512MB version though? As I said before, I know the 512MB was laden with issues, but I haven't been able to find anything in regards to the 1024MB other than the Newegg user review above. And on its own it doesn't really say too much either.

krille · Post by **krille** » Sun Dec 14, 2008 8:13 am

A "Jim M0rrison" over at XS ( http://www.xtremesystems.org/forums/sho ... p?t=209830 ) is confirming that the "PCS" design has been changed. In fact, he goes as far as to say that the new revision is not only of cheapo quality but actually ship downclocked to the reference clocks of 750, even though Powercolor's specifications promise 780 Mhz. From the looks of it, perhaps these "PCS" cards should be avoided altogether?

rpsgc · Post by **rpsgc** » Fri Dec 19, 2008 7:31 am

I have just discovered the perfect heatsink for the HD4870's VRMs!!

Zalman ZM-RHS70

It was MADE for the HD4870's VRMs! But it doesn't effin' fit! It's too tall to fit under the Accelero

Maybe Thermalright's HR-03 PWM heatsinks might work
http://www.thermalright.com/new_a_page/ ... s/9800.JPG

WR304 · Post by **WR304** » Fri Dec 19, 2008 12:13 pm

If you've got a Zalman ZM-RHS70 heatsink it's only made of aluminium. The easiest way to get it to fit would be to cut down the ZM-RHS70 fins so it fits under the Accelero S1. So long as you have the right tools it will only take a few minutes to trim them down.

It looks like you could maybe bend some fins so that it slots in between the Accelero S1 fins too.

rpsgc · Post by **rpsgc** » Sat Dec 27, 2008 2:15 am

I tried the stock red cooling plate but my Accelero doesn't sit properly with it in place. Doesn't make proper contact with the GPU.

sputnik99 · Post by **sputnik99** » Fri Jan 23, 2009 9:48 pm

rpsgc wrote:I tried the stock red cooling plate but my Accelero doesn't sit properly with it in place. Doesn't make proper contact with the GPU.

It should make contact.

I did the same thing and kept the backplate and slapped on a Accelero S1. A small section of the backplate rubbed up against Accelero but I continued to screw in the heatsink and its working really well.

Temperatures gone down from 50 degrees idle to 39 degrees. I use a 120mm fan with a fan controller to reduce the speed to less than 700 RPM. Barely audible and worked just fine... gaming and all.

nutball · Post by **nutball** » Sat Jan 24, 2009 12:04 am

sputnik99 wrote:I did the same thing and kept the backplate and slapped on a Accelero S1. A small section of the backplate rubbed up against Accelero but I continued to screw in the heatsink and its working really well.

Indeed. I just bent the ends of some of the S1 fins to allow the backplate to fit.

nafets · Post by **nafets** » Sat Jan 24, 2009 5:31 am

Cooling the HD4870 GPU with the Accelero S1 is never a problem. The cooler is more than enough with a single 120mm fan.

The problem is the VRMs. Using the half-ass VRM heatsinks with the Accelero S1/Twin Turbo on the HD4870 is just asking for trouble. It's highly recommended if you have a reference HD4870, that you try and use the stock red plate along with the Accelero S1. The reference 3-phase VRM designs need excessive cooling surface to properly dissipate the heat they put out. The small and ineffective heatsinks that are put on with aftermarket coolers do not provide enough cooling surface, even with a high speed 120mm fan blowing on them.

But using the Accelero S1 + stock red plate proves more effective and can be a fairly good replacement over the reference cooler...