Where is VRM on HD4870 ?

[Sony190]

I want to change the cooler on my Powercolor 4870 and need to know where the VRM is and what it looks like. I have a ARCTIC COOLING Accelero TWIN TURBO VGA Cooler For Radeon HD 4870.

[EarthDog]

Well I googled and found this link: http://en.expreview.com/img/2008/09/02/stcom.co.kr__8400_12.jpg
Its the 6 grey items in the picture Im pretty sure.


Here is a reference board, its the 2 small black items and the 1 larger black item that says VITEC on them.
http://en.expreview.com/img/2008/07/21/image007_1.jpg

[baditude_df]

I think that the VRM consisists of the Chokes and the Mosfets no? Voltage and current regulators. I could be wrong. I'm not sure exactly where the actual temperature sensor is located, but it's definitely in the area you posted the picture of.

Anyway, it's the area underneath the black Heatsink in this picture:
http://img191.imageshack.us/img191/404/imgp0539sywnac.th.jpg (http://img191.imageshack.us/i/imgp0539sywnac.jpg/)

You could likely put on an I&H 4870 cooling kit (http://www.petrastechshop.com/cuhdcokitbyi.html). As per the maker, you only need 4.7mm of clearance and they seem to do a very good job.
You just have to make sure the screw holes will like up, and that all depends on which PCB you have.

[Alien432]

These are the VRM (voltage regulator modules) yellow area, they need to be sinked.

http://i390.photobucket.com/albums/oo350/Alien432/image007_1.jpg

Use these: http://www.jab-tech.com/Enzontech-Mosfet-Heatsink-MOS-C1-pr-4112.html
http://www.jab-tech.com/images/T/t_4112.jpg

or :http://www.petrastechshop.com/swmcmohepof4.html
http://ep.yimg.com/ca/I/yhst-65556269779593_2068_55004878

or:http://www.zalman.com/ENG/product/Product_Read.asp?idx=335
http://www.zalman.com/DataFile/product/ZM-RHS70_b_02.jpg

[xtkxhom3r]

Alien432 is right those are the vrms and make sure you get the biggest heat sinks you can fit on them because those things are very hard to tame

[baditude_df]

That's the picture I was looking for ALien. That's the original reference design that most every heat sink and block will work with.
What about attaching separate HEatsinks though? I know that tape that comes with them is pretty weak stuff, but it's nice if you want to take it off later. Has anyone ever tried thermal adhesive? If so, what was the result?

[madhatter256]

If the OP can post the brand/model of 4870 he has, then we can better help him on what VRM cooling he needs. Nowadays a lot of manufacturers use different arrangments of VRMs on the card.

[baditude_df]

Yep, I've owned 3 different brands/revisions and they were all vastly different. Only the original would take a full coverage water block. And only two of them would fit the I&H Cooling kit.
The OP says he has a PowerColor, and I know they have had a few different coolers, I'm not sure about the PCB reference though.
Sometimes, the only option you're left with is to go with seperate sinks on all the mosfets.

[xtkxhom3r]

im sure their arranged differently on different cards but they all look the same or really really similar and they all close to the power connectors so you cant really miss them....

[baditude_df]

The Mosfets are almost always the same, chokes can vary quite a bit. But the layouts, screw hole placements and dimentions(clearance wise) are what I'm talking about.
Regardless, they are typically always on the power plug side of the card, just like the Ram is always around the GPU. I just wish the OP would post a pic of his card, or google PowerColor HD4870. I'm sure there's a good naked picture out there somwhere.

[Super Nade]

I think that the VRM consisists of the Chokes and the Mosfets no? Voltage and current regulators.

Not entirely correct. The MOSFETs, chokes and caps form one part of the VRM. The most important part would be the buck regulator and the associated feedback circuitry. Chokes and Caps are post processing elements, i.e the filtering system.

[baditude_df]

Nicely put. That list was not all inclusive, it was more to say that it's not just the Voltage Regulators (ie: the part under the sink/MOSFETs), in response to the post above it.
Obviously you would need to connect everything somehow, not only from the VRM to the CPU/GPU but also from the 12v Plug to the VRM. It's alot of traces in PCB and circuitry and I have no clue what it's all called, lol! :)

[Sony190]

The VRM are under the Heatsink at the end of the video card?

I have this video card http://www.newegg.com/Product/Product.aspx?Item=N82E16814131140

I have a AFB1212 fan on top of the video card fan and receive a constant 41 C temp, with out the extra fan the video card runs at 51 C.


The review that i saw for the ARCTIC COOLING Accelero TWIN TURBO VGA Cooler For Radeon HD 4870 claim to have dropped the temps 15 c so Im hoping for better temps