Radeon HD 4850 - Heat

[Carel]

Hi all, I know I sometimes sound like a fool, but, here goes. Ok, so I Volt-modded my Radeon HD 4850 to OC to 800Mhz GPU @ 1.4V & 1100 @ 1.9V memory. I used the stock cooler, while running @ these settings (In winter time). So, I decided to buy the TRAD2 & the Asus Arctic Square. Wel, I'm quite Impressed with my TRAD2, because, the new temps are always around 28 / 29C & never, never goes higher than 45C. So, even if I run the GPU under stress @ 800Mhz, it stays under 50C (around 40C), & the RAM sinks are also cool. But, here are the problem : The VRMs (Voltage Regulating Modules). The MOSFETS really, really, really gets damn hot, even with proper heatskinks applied. So, what I did then : I sawed off the little piece of the heatsink, (my old ATi cooler) the part that covers the 8 MOSFETS for the GPU & then screwed it to the VRMs, but even that couldn't keep them cool. Really, those MOSFETS do get hot, so hot that it'll burn you. I'm just afraid of that, because if they fail, they'll send 12V staright to the GPU & blow it! The MOSFETS for the RAM are quite cool, so they are not at stake (there are only 2x of them). This 4850 gets a 3DMARK Vantage score of >=P7700. So, if there is anyone with A TRAD2 on an ATi Radeon HD 4850, then I want to ask you : How did you cool the VRMs? Will the MOSFETS blow if they overheat? Please, anyone that can help me? I wan't to know how can I cool down these Regulators? I doubt if the GPU are at stake, since it stays at an excelent temperature, even at full load.

 

[Freak]

I have done a bit of googleing for ya.

Seems that they are meant to be hot. Are you able to return it back to stock and note the temp difference between the two?

Isnt the artic square a cpu cooler? Idle temperatures mean nothing btw. Its load that matters.

The cooling that you have appears to be focused on the core. Why not look at something in the styles of The Accelero Twin Turbo that way you will be cooling the whole card.

I would look at getting propper heat sinks for them. That may make a world of difference. Then think about getting an airflow through them

 

[Carel]

Yes, before using the TRAD2, the temps were 56C @ idle & reached up to 90C under load (stock). Now, the GPU's temps are 28C (idle) & like I said, never, never goes above 46C, even when overclocked @ 800Mhz. So, the GPU wouldn't blow because of heat... Anyways, the reason for my fear is : http://www.techpowerup.com/index.php?69799 --> it sounds like there were MOSFETS of the ATi 4850 that have blown before? Thats why AMD slowed down Furmark torture test in Catalyst 8.8.

What I was thinking to cool the MOSFETS : I am wondering, there are 8 mosfets. They are in groups of 4. So, they are in parallel, 2x + 2x + 2x + 2x --> & these four groups are using 4 coils, each pair are using 1 coil. The output of one pair (2x MOSFETS in parallel), goes through 1 coil. These 4 coils, marked as L1 - L4, are right next to the MOSFETS. The coils also get damn hot, but they are not likely to burn, since they can handle very, very high temps. So, I was thinking, maybe I can desolder the 4 coils & solder wires to them & maybe move them to a different location, maybe with their own heatsink? Right now, they (Coils) are sharing the same heatsink with the MOSFETS. Maybe this can work? Don't worry, my warranty is already voided a long time ago... The mosfets on the 4850 are very, very tiny & are as flat as 1mm ea. I compared the OC temps to the stock temps (MOSFETS only) & there are quite a huge difference. So, it'll need more cooling, if I don't want to send 12V to the GPU...