Underclocking the 4850

[BathroomFeeling]

Seeing as 4850s hits the golden spot, I want to ask if anyone has tested underclocking it for any duration of time such that it maintains stability?

The problem is that I live in a hot city, sometimes too hot, reaching a top dry heat of 35C (95F) during certain times of the year and I don't use air-conditioning where the PC is. So as you can imagine, a constant heat generating component does not help much. Ideally I would purchase a mediocre card in a heartbeat if it means lower heat generation. Unfortunately I am a breed that also loves gaming, thus my dilemma.

What I would like to do is purchase an HIS IceQ 4850 with that nice dual-slot cooler throwing all that useless heat outside the case. Since that warms up the room, its not ideal. But it's a compromise I'm willing to make if it means operational stability and lengthened vitality for my expensive electronics. The bandaid thus is the reduction of heat through uncerclocking. I don't see the need to run the card at maximum speed if all I'm doing for most of the day is browsing the web. If that also means reduced power consumption, well all the better.

So what program would I use for such a task? I suppose it would also need to control the fan. I don't plan to do any overclocking with any of my components. It'll either be factory clocked, or underclocked. Thanks.

 

[octopus41092]

It's not that bad. If you crank up the fan speed it'll run in "safe" temperatures. I couldn't stand looking at that number so I slapped a Accelero S1 onto it along with a 120mm fan. Now I get around 51C full load but with it overclocked to 700MHz Core.

 

[Dadofamunky]

Originally posted by: octopus41092
It's not that bad. If you crank up the fan speed it'll run in "safe" temperatures. I couldn't stand looking at that number so I slapped a Accelero S1 onto it along with a 120mm fan. Now I get around 51C full load but with it overclocked to 700MHz Core.

How hard was it to do that? I have the same card and I'm also not happy with the temps.

 

[error8]

Originally posted by: Bobby1978
Seeing as 4850s hits the golden spot, I want to ask if anyone has tested underclocking it for any duration of time such that it maintains stability?

The problem is that I live in a hot city, sometimes too hot, reaching a top dry heat of 35C (95F) during certain times of the year and I don't use air-conditioning where the PC is. So as you can imagine, a constant heat generating component does not help much. Ideally I would purchase a mediocre card in a heartbeat if it means lower heat generation. Unfortunately I am a breed that also loves gaming, thus my dilemma.

What I would like to do is purchase an HIS IceQ 4850 with that nice dual-slot cooler throwing all that useless heat outside the case. Since that warms up the room, its not ideal. But it's a compromise I'm willing to make if it means operational stability and lengthened vitality for my expensive electronics. The bandaid thus is the reduction of heat through uncerclocking. I don't see the need to run the card at maximum speed if all I'm doing for most of the day is browsing the web. If that also means reduced power consumption, well all the better.

So what program would I use for such a task? I suppose it would also need to control the fan. I don't plan to do any overclocking with any of my components. It'll either be factory clocked, or underclocked. Thanks.

Underclocking your card when it's idle doesn't do quite about anything in terms of reducing power consumption. If you could reduce the voltage, that would mean something, but not too much. A videocard becomes a room heater only when it's under load. In idle its power consumption is minimal.

 

[shangshang]

Last time I said that I live in a hot place and I don't run AC and this was causing my 4850 to freeze up randomly, the ATI fanboys scolded me telling me that I was crazy not to use AC, and it was not ATI's fault. Anyway, hopefully your card won't freeze up since it's double slot.

 

[error8]

Originally posted by: shangshang
Last time I said that I live in a hot place and I don't run AC and this was causing my 4850 to freeze up randomly, the ATI fanboys scolded me telling me that I was crazy not to use AC, and it was not ATI's fault. Anyway, hopefully your card won't freeze up since it's double slot.

Well if you had a room temp of 110 F, then yes, it was your fault.

 

[nevbie]

You can use ATI Tray Tools beta to change the 4850 clockspeeds/GPU voltage while in windows.

I can underclock mine to 160/500 CORE/MEMORY from the default 625/993. I can also change the voltage from 1,044 to 1,006 in ATT, but they may represent the same real voltage.

Doing those changes lowers the card temperature ~2C when comparing idle modes for me.

This card can swap between 3 different core/memory/voltage modes, based on load. At default it changes to 500/750 at idle, so it effectively uses only 2 modes. The BIOS of the card seems to control these details. The BIOS can be changed, but it needs some caution.. backuping old bios, having a spare pcie graphics card in case the flash fails is what I would require from myself before messing with it. A program called RBE (radeon bios editor) is an useful tool regarding BIOS changing. For automatic underclocking/volting you need to use some kind of automatically starting application or just edit the BIOS (I plan to go the bios route.. later).

 

[Ares202]

Originally posted by: error8

Originally posted by: shangshang
Last time I said that I live in a hot place and I don't run AC and this was causing my 4850 to freeze up randomly, the ATI fanboys scolded me telling me that I was crazy not to use AC, and it was not ATI's fault. Anyway, hopefully your card won't freeze up since it's double slot.

Well if you had a room temp of 110 F, then yes, it was your fault.

It says in the manual of hot componenets such as cpu and gfx that the product is not suitable for tempretures over 40C sometimes 45C, so dont blame ATI alone for this

if you dont like having AC on at that room tempreture and want a fast pc try watercooling thats all i can say

 

[chizow]

If you're considering downclocking the 4850 in order to maintain manageable temps, I'd just save yourself the hassle and get a 9800GTX+. Not only will it run cooler with a far superior cooler, but it will undoubtedly be faster as well compared to an underclocked 4850.

 

[nevbie]

A 9800GTX+ consumes more power than a 4850 both in idle and in load*, so I would expect the 4850 to generate less heat.

It's more of a feeling thing though, as people who bought a 4850 and have it unknowingly running at 80C are probably happy with it.

Is the goal to reduce the total amount of power used/heat generated or the maximum heat level reachable by the part?

*I checked some reviews and it seems that the difference is minimal though.

 

[Ike0069]

I was worried about the temps and almost went with a 9800GTX for that reason, but I have no problems with heat since I the increased fan speed. Really happy with this card.

 

[mancunian]

Originally posted by: Dadofamunky

Originally posted by: octopus41092
It's not that bad. If you crank up the fan speed it'll run in "safe" temperatures. I couldn't stand looking at that number so I slapped a Accelero S1 onto it along with a 120mm fan. Now I get around 51C full load but with it overclocked to 700MHz Core.

How hard was it to do that? I have the same card and I'm also not happy with the temps.

I did exactly the same as octopus41092 and for the same reasons, didn't like looking at those temps. It now idles at 32c, loads at about 45c. Quiet as anything with a 140mm fan @ 700/1100.

And it's not hard to do, basically if you do this and mount the card by laying the cooler on its back with heatsink surface facing upwards, and then subsequently lower the card onto it, not the other way around (lowering the heatsink onto the card). Doing this means the card sits there nicely while you screw down the sink, easy to do too as the screw holes face upwards.

Make sure to put ramsinks on the memory and voltage regulators, basically anything that had a white 'pad' when using the stock heatsink.


It's the best thing to do with this card if you get one with a stock cooler.

 

[BathroomFeeling]

Thanks for the comments. So basically in addition to lowering the clock speeds, I would also need to lower the voltage? Its sounds strange for the voltage to start at 1.044... how come it isn't at 1.000 exactly? How about if I lowered it to 0.9v in addition to lowered clocks, will such a reduction be stable?

My previous attempts at video card underclocking on my ATI 9800Pro proved less than successful. Even though the clocks were lowered by a few percentage points, sometimes even fractions of a percent, it was always unstable. At times everything appeared good, but quite suddenly for no good reason, it would either reboot the system or crash it with funny colors strewed about in the display. This was quite puzzling to me, as only the clocks were manipulated. It should have been more stable if anything. I also wasn't able to adjust the fan speed on the thing, although perhaps that's probably a feature available only on modern cards? If a fan is replaced with a 3rd market one, as in the case of the HIS IceQ4, would one still be able to adjust it through software programs?

As for the Accelero, it was on my consideration list for the longest of times, but I have since decided on the dual slot. I am apprehensive about using the thing since it appears to utilize the same air for cooling and heat dispersal, I don't think it would be of much help unless my room temperature was in the low 20Cs.

Thanks again guys.

 

[nevbie]

Well I lost the video signal after undervolting it below ~1V, so I guess the stock voltage is already low enough. No need to touch that. Basically underclocking the card to 160/500 saves you few degrees and that's all. It's easy to try to do complex plans before you have the hardware, but after you get it, things get quite simple.

I'd imagine the custom fan can be controlled as well, but can't say for sure.