HD4850 and thermal compound

if i were to remove the stock heat shroud and apply arctic silver 5, do i need to put some on the ram chips as well, since the shroud covers it?

To my knowledge I don't think so.. I could be wrong but it doesn't sound right.

If there was no paste there to begin with, then no I definitely would not do that - as far as I am concerned thermal compound is just for CPU, GPU, and for some chipset heatsinks like a north bridge? I never heard of anyone putting it on the ram chips though.

Typically, vRAM has heatsink material on it. You could put a small amount on if you removed the current stuff. However, I am not sure how ATi designed it. It won't hurt it if you use Artic Silver: Ceramique. Don't use AS5 though, as you risk a short circuit if it gets off the very small vRAM modules.

It's pad based. Leave the pads be. Just do the core.

Why is it that I have never trusted pad cooling?

Because under normal circumstances, it's shite. However, as you well know, vRAM doesn't have to worry so much with cooling, and almost anything will work-pennies, little Zalman RAMsinks, etc. As such, there's little reason to waste thermal compound on something that is already completely adequately cooled.

If EddyEK sends thermal pads for his FC blocks, it's good enough for me.

I would still compound them, but meh, I am a perfectionist. So meh.

The only reason pads should be used over TIM is in the event of uneven contact. Some fullcover GPU heatsinks aren't completely flat; the pads are pulling double duty both as a thermal medium and to fill in the gap.

I wouldn't touch it. These cards just run hot. I've been down this road before and have replaced stock thermal compounds, but you just don't gain anything from it. A lower temp won't make it better or produce less heat.

If the card doesn't work right, just get a replacement.