ATI 4850/4870 voltmod thread

[aussie-revhead]

You did select the 2nd device when you tried to OC the 2nd card?

Yes and it gave an error about second card not suuported. I have seen this reported elsewhere too.

You shouldn't be CPU limited in almost any games/settings worthwhile with a pair of those cards. Can you give me some numbers? Like Crysis at high settings or the like. It sounds odd that the cards perform worse at a higher GPU clock.

Is crysis bench standalone or do I need to buy the game ? I have tested 3D06 and vantage but dont get anything worthwhile out of a gpu clock increase.

No, but honestly I don't really trust the RBE BIOS Editor to mod BIOS'. I do it manually in a HEX editor. Flashing is simple if you look up how to make a USB stick bootable and read a bit about the basic commands of the flashing program. You can flash cards in Windows I think, but I use DOS because it is considered safer. Just make sure you get the latest ATIFlash and check if the BIOS you are trying to flash is 128kb in size and not 64kb.

Yeah I want to crank them up in software for benching then put them back . Maybe I have to revisit nvidia .

[keninishna]

i can have 885/1200 for crysis and furmark and 900/1200 for 3dmark 06,05,01 and 910/1200 for 03 with 1.45v, on air (accelero s1)

Is that with a 4870 or 4850? If its a 4870 then our problems might be heat related even though gpu-z is reporting pretty good temps.

[rym]

nevermind

[revogamer]

Is that with a 4870 or 4850? If its a 4870 then our problems might be heat related even though gpu-z is reporting pretty good temps.

sorry, yeah its a 4850 not a 4870

[SNiiPE_DoGG]

i booted up my voltmodded 4870 today and it works! yay so if anyone is looking for an example mod you can use mine posted earlier in the thread (link) i haven't tested voltage but it should be around 1.36v. ill have more pics and benches for you guys sometime in the next 24 hrs

cheers, SNiiPE

[ibuycheap]

Anyone with a stock 4850 run furmark. I put my mcw60 on it plus ram sinks on the pwms and it won't last more than a minute at stock speeds. The gpu is at 33 idle 40 load. Any idea what could be the problem?

[babalouj]

crashing furmark is a known problem for ati 38XX and 48XX series cards. It would be best to not use this as a stability test if you are experiencing these crashes. Some people with ati cards can run it fine but there are tons of people with the same complaint of it failing.

[stangracin2]

mine was topping out at 72 C for furmark then i just got bored and played CS

[aldamon]

Anyone with a stock 4850 run furmark. I put my mcw60 on it plus ram sinks on the pwms and it won't last more than a minute at stock speeds. The gpu is at 33 idle 40 load. Any idea what could be the problem?

My PSU squeals loudly with both Furmark/ATITool and my overclocked 4850 eventually crashes to a black screen. Games, RTHDRIBL, Video Card Stability Test, 3DMark, and everything else run fine. There's something wrong there and since I don't play Furmark/ATITool, I just don't care.

[SetteUltras]

Anyone with a stock 4850 run furmark. I put my mcw60 on it plus ram sinks on the pwms and it won't last more than a minute at stock speeds. The gpu is at 33 idle 40 load. Any idea what could be the problem?

Use a strong fan towards ram sinks and pwms. See if that happens again. I believe it wont.

[Barr3l Rid3r]

3DMar06 HD4850 @ 650 /2200Mhz

http://service.futuremark.com/compare?3dm06=7556384

3DMark06 HD4850 @ 835/2000Mhz

http://service.futuremark.com/compare?3dm06=7549757

[Laykun]

Jesus man, get some sinks on those voltage regulators before you blow the thing.

[binormalkilla]

Jesus man, get some sinks on those voltage regulators before you blow the thing.

LOL you're not lying!

So I'm going to practice soldering some before I attempt the vGPU mod on my 4850s.....I have them flashed to 750/1125 with 1.2V (well I guess, haven't tested with DMM yet).

Are you guys using wire from spare SATA cables for volt mods? I've read that's good to use because they're so thin. If not SATA wire then what AWG? Thoughts? Suggestions?

I know this doesn't specify the number of turns, but does this look about right for the vGPU mod?

[Moty]

What are the good results of hd4850 overclocking on air, not for benching, but for 24/7 usage?

[r4st4m4n]

Are you guys using wire from spare SATA cables for volt mods? I've read that's good to use because they're so thin. If not SATA wire then what AWG? Thoughts? Suggestions?

Fans wires are generally thin or I've also used some wire from an old case. The one used for the front panel connection.

Or you can always buy few meters ..

[Barr3l Rid3r]

E


33ºC Idle @ 840Mhz / 1.32V


http://service.futuremark.com/compare?3dm06=7580874

39ºC @ 900Mhz / 1.45V Full

[binormalkilla]

Fans wires are generally thin or I've also used some wire from an old case. The one used for the front panel connection.

Or you can always buy few meters ..

Yea I have no problem buying it, what AWG though? I have a bunch of front panel connectors.........I'll probably practice with the leftover stuff and buy some spooled wire.

[sandwichamwin]

I put together a little blog guide thing of volt modding the 4850. It might help someone who is new anyway. Click here.

I managed to bench at 975mhz with an MCW60.


Just finished vmodding the 4870 then...


So... wonder how many volts it takes to kill these things?

[jason4207]

E


33ºC Idle @ 840Mhz / 1.32V


http://service.futuremark.com/compare?3dm06=7580874

39ºC @ 900Mhz / 1.45V Full

You may want to sink those 8 black chips as well...

Yea I have no problem buying it, what AWG though? I have a bunch of front panel connectors.........I'll probably practice with the leftover stuff and buy some spooled wire.

30AWG is what I use.

[MonsterMash]

Hi,
actually i have 2 3870 in xfire, pencil vmodded and overclocked to 1012mhz, water cooled. Now i'm buying a 4870, and my purpose is to make pencil vmod and overclock it at the same freq (i want to broke the wall of 1 ghz ), always liquid cooling it, of course. Do you think it's possible?.

Thank you.

[Barr3l Rid3r]

I put together a little blog guide thing of volt modding the 4850. It might help someone who is new anyway. Click here.

I managed to bench at 975mhz with an MCW60.


Just finished vmodding the 4870 then...


So... wonder how many volts it takes to kill these things?

How many volts did u use for 975Mhz?

[STaRGaZeR]

A vddc pencil mod for the 4870 would be possible?

[sandwichamwin]

How many volts did u use for 975Mhz?

Approx 1.42v


I just had a quick bench with the 4870. Seems like it doesn't like voltage as much as the 4850. Max on stock volts was 890mhz. Bumped the voltage by .1v and i hit 950mhz. Then not a single mhz more, regardless of voltage.

Anyone else experiencing similar things? Or have i just hit the limit of the card?

[SNiiPE_DoGG]

Approx 1.42v


I just had a quick bench with the 4870. Seems like it doesn't like voltage as much as the 4850. Max on stock volts was 890mhz. Bumped the voltage by .1v and i hit 950mhz. Then not a single mhz more, regardless of voltage.

Anyone else experiencing similar things? Or have i just hit the limit of the card?

i will have some comparisons of my voltmodded 4870's (fixed 1.36v) in a few hours hopefully

[binormalkilla]

I put together a little blog guide thing of volt modding the 4850. It might help someone who is new anyway. Click here.

I managed to bench at 975mhz with an MCW60.


Just finished vmodding the 4870 then...


So... wonder how many volts it takes to kill these things?

Hats off to ya.....excellent little guide