ATI 4850/4870 voltmod thread

[Søndergård]

Could that be what causes my problem which is as followed:

My Powercolor 4870 is under water with the new EK FC block. Before vGPU mod I ran it at 850/1000.

Today I did the vGPU mod, and where ATI Tool would artifact above 850 before, I was now able to run ATI tool artifact free at 940MHz. (See picture).

My problem is, that eventhough ATI tool runs flawless, no game will run for more than a few secounds. Everything above aprox 1.37v will make the screen go black or the displaydriver to stop working.

It dosent matter if I only uses the same 850mhz as I did before the mod.

Lowering mem speed dosent do anything for me either..

Would it make any sense to try another BIOS?

Really hope you guys are able to help me out here

[Dirton]

Søndergård
How far does your adapter go with furemark?

[Søndergård]

Søndergård
How far does your adapter go with furemark?

Furmark gave me the after a few sec.

[dejanh]

^ Yeah, that's the same thing I got as I turned up the volts. Does your D601 diagnostic LED ever turn on when stuff crashes? I got it to turn on from time to time, indicated "critical core power failure". Only happens if you set voltages higher than 1.35V-1.37V on idle. It was very strange behavior indeed. I noticed that at this point VRM temps are also extremely high. Either way, it will not really matter what your clocks are in this case. The card will crash no matter what. If you lower the volts you will be fine. It must be that some OCP or OVP thing is kicking in...

[Søndergård]

^ Yeah, that's the same thing I got as I turned up the volts. Does your D601 diagnostic LED ever turn on when stuff crashes? I got it to turn on from time to time, indicated "critical core power failure". Only happens if you set voltages higher than 1.35V-1.37V on idle. It was very strange behavior indeed. I noticed that at this point VRM temps are also extremely high. Either way, it will not really matter what your clocks are in this case. The card will crash no matter what. If you lower the volts you will be fine. It must be that some OCP or OVP thing is kicking in...

I think you just saved my day I tryed lowering the voltage to 1.35 and now Furmark dosent crash imidiatly. I was not ablo to run 900MHz core at that voltage, but at 1.375 I am running Furmark at 900Mhz. So far 5 min..

Now I just need to make some finer adjustments and find out how high I can go without the "problem" is kicking in.

Thanks again.

[dejanh]

^ No worries. Glad I could help.

Which brand is your card (e.g., HIS, PowerColor, Diamond, Sapphire)?

Also, are you able to run the memory at least 1100 at that core speed? I found that the highest stable I could achieve with the Diamond 4870 XOC BE on air was 875/1125 at 1.358V core, 1.501V memory and 850/1150 at slightly different voltages. Either way, I did not notice almost any performance gain when compared to say 825/1125...

[kur¡]

kur¡,
Go here.
Look for "VDDC measure" in the pic...

Thanks

[Søndergård]

^ No worries. Glad I could help.

Which brand is your card (e.g., HIS, PowerColor, Diamond, Sapphire)?

Also, are you able to run the memory at least 1100 at that core speed? I found that the highest stable I could achieve with the Diamond 4870 XOC BE on air was 875/1125 at 1.358V core, 1.501V memory and 850/1150 at slightly different voltages. Either way, I did not notice almost any performance gain when compared to say 825/1125...

Well I have been using the Diamond 4870 XOC BE and ASUS TOP BIOS. No real difference here..

Hmm, the 900MHz core I can't get stable. I can get Furmark stable but then Crysis will fail, or the opposit.

Looks like the best possible all stable is about 880mhz.

The mem I havent messed with yet. Stock/water is only accepts about 1025, but I am considering modding the mem as well.

Quite dissapointet that the vmod only gave me about 30 Mhz from the non mod 850mhz oc I had before Though I am quite sure it is possible to bench much higher, as I was able to run ati tool artifact free at 940Mhz.. Maybe not..

Is my problem normal or? Is it possible that a mod will remove the OVP (If thats what causing my problem?)

What do you cool your card with? And how musk can I expect to gain in mem mhz when max stock is about 1025? (Know its hard to predict, but if it is just 25Mhz, I wont even bother). To me 24/7 and stability is nr.1

[dejanh]

Well I have been using the Diamond 4870 XOC BE and ASUS TOP BIOS. No real difference here..

Hmm, the 900MHz core I can't get stable. I can get Furmark stable but then Crysis will fail, or the opposit.

Looks like the best possible all stable is about 880mhz.

The mem I havent messed with yet. Stock/water is only accepts about 1025, but I am considering modding the mem as well.

Quite dissapointet that the vmod only gave me about 30 Mhz from the non mod 850mhz oc I had before Though I am quite sure it is possible to bench much higher, as I was able to run ati tool artifact free at 940Mhz.. Maybe not..

Is my problem normal or? Is it possible that a mod will remove the OVP (If thats what causing my problem?)

What do you cool your card with? And how musk can I expect to gain in mem mhz when max stock is about 1025? (Know its hard to predict, but if it is just 25Mhz, I wont even bother). To me 24/7 and stability is nr.1

My cooling is a HR-03GT with a 92mm fan on top with stock HR-03 sinks on memory and VRM. I am looking to install this guy http://www.thermalright.com/new_a_pa...50aHVzaWFzdA== (an HR-09 Type 4) onto the VRMs. I already tried the HR-09 Type 2 but its wider 15.5mm base is too wide and cannot fit properly onto the VRMs. The Type 4 guy has a 12mm wide base so it should fit. I found that the card is extremely sensitive to upping the voltage on the core and the memory. When you do both you get BS much faster. I think in this case it is some kind of OCP kicking in. You will see that yourself if you try to voltmod the memory in addition to the core. With such a high core at 880MHz or 900MHz you will not be able to OC the memory much from your 1000MHz, or at all. I would say that you will get artifacts as soon as you hit over 1050MHz so if 50MHz is worth it for you to mod things go ahead. Unfortunately the 4870 XOC BE does not OC that well. I am not sure about other cards but I think most 4870 have a problem getting over 850MHz core and about 1125MHz - 1150MHz memory.

I also found the same thing you did in terms of ATITool/FurMark and games. If I stabilize ATITool can be artifact free with high voltage at high core clocks with good cooling. However, FurMark crashes at those voltages so it forces you to go with lower voltages if you want higher clocks for FurMark. These higher clocks at lower voltages however cause instability in games as your lower volts now are not sufficient for stable operation in games so you need to lower your clocks as well. It is a really stupid cycle that I found. Hence the reason why I had to stabilize at the clocks I mentioned before. I have worked on this card for > 12 days straight with constantly the same results using three different cooling systems and several cards. All were with same results.

To summarize, what you will find is that if you up the memory voltage and memory clock you will have to lower your core clock and potentially core voltage, and vice versa. The highest stable overall combination will be something in between 850/1150 and 875/1125 (notice the trade-off between core and memory clocks ). Ironically, I found that in games the best performance was at 825/1125 clocks and that anything higher did not yield anything significant in terms of FPS (some higher clocks even yield less ) as well as that the performance at higher clocks did not justify the added heat output and power consumption of the board.

Edit: One other thing to note is that the Qimonda memory chips are 40X, so they are rated for max 4000MHz with critical maximum voltage being 2.0V (stock is 1.501V). Running them at 4400MHz or higher is already 10%+ OC on the memory so it is not that strange that it would be causing problem when trying to push it very high. Some people can run very high since they do not care about 100% stability and they do not even notice some artifacts in games so for them going 4600MHz - 4800MHz with high core clocks (> 850MHz) is okay.

Edit 2: I would not hold my breath on the OVP/OCP being disabled in the future using any BIOS or other hard-mod method really. I found in the past that there is usually just too much work involved in doing this with mixed results at the end. If anything, it severely increases your risk of blowing up the board.

[Søndergård]

My cooling is a HR-03GT with a 92mm fan on top with stock HR-03 sinks on memory and VRM. I am looking to install this guy http://www.thermalright.com/new_a_pa...50aHVzaWFzdA== (an HR-09 Type 4) onto the VRMs. I already tried the HR-09 Type 2 but its wider 15.5mm base is too wide and cannot fit properly onto the VRMs. The Type 4 guy has a 12mm wide base so it should fit. I found that the card is extremely sensitive to upping the voltage on the core and the memory. When you do both you get BS much faster. I think in this case it is some kind of OCP kicking in. You will see that yourself if you try to voltmod the memory in addition to the core. With such a high core at 880MHz or 900MHz you will not be able to OC the memory much from your 1000MHz, or at all. I would say that you will get artifacts as soon as you hit over 1050MHz so if 50MHz is worth it for you to mod things go ahead. Unfortunately the 4870 XOC BE does not OC that well. I am not sure about other cards but I think most 4870 have a problem getting over 850MHz core and about 1125MHz - 1150MHz memory.

I also found the same thing you did in terms of ATITool/FurMark and games. If I stabilize ATITool can be artifact free with high voltage at high core clocks with good cooling. However, FurMark crashes at those voltages so it forces you to go with lower voltages if you want higher clocks for FurMark. These higher clocks at lower voltages however cause instability in games as your lower volts now are not sufficient for stable operation in games so you need to lower your clocks as well. It is a really stupid cycle that I found. Hence the reason why I had to stabilize at the clocks I mentioned before. I have worked on this card for > 12 days straight with constantly the same results using three different cooling systems and several cards. All were with same results.

To summarize, what you will find is that if you up the memory voltage and memory clock you will have to lower your core clock and potentially core voltage, and vice versa. The highest stable overall combination will be something in between 850/1150 and 875/1125 (notice the trade-off between core and memory clocks ). Ironically, I found that in games the best performance was at 825/1125 clocks and that anything higher did not yield anything significant in terms of FPS (some higher clocks even yield less :s as well as that the performance at higher clocks did not justify the added heat output and power consumption of the board.

Well, hmm I think I will sleep on it. But I guess I will remove the hardmod and flash back to 850/1000 with std. voltage on everything.

No regreds though, it was my first hardmod, and it was fun as hell! Now I am just hoping I can remove the solderings and keep my waranty intact.

[dejanh]

Well, hmm I think I will sleep on it. But I guess I will remove the hardmod and flash back to 850/1000 with std. voltage on everything.

No regreds though, it was my first hardmod, and it was fun as hell! Now I am just hoping I can remove the solderings and keep my waranty intact.

Use a solder wick and it comes of like a charm I did that already a bunch of times. Then after you are done clean the board with some alcohol or (my favorite) acetone

[Rickpatbrown]

How do you guys solder? Do you place the tinned wire to the pad/leg and then heat the wire? Or do you heat the pad and the wire at the same time? I know I want to avoid cold joints, but I don't think I can hit the pad and the wire at the same time. When I solder, it seems that the tip of the tinned wire becomes like the iron and heats the solder on the pad well.

Sorry, I'm new to this and trying to avoid failure. I've been practicing a lot though. This is hella fun!

BTW I'm trying to mod my 4850's.

[Søndergård]

How do you guys solder? Do you place the tinned wire to the pad/leg and then heat the wire? Or do you heat the pad and the wire at the same time? I know I want to avoid cold joints, but I don't think I can hit the pad and the wire at the same time. When I solder, it seems that the tip of the tinned wire becomes like the iron and heats the solder on the pad well.

Sorry, I'm new to this and trying to avoid failure. I've been practicing a lot though. This is hella fun!

BTW I'm trying to mod my 4850's.

Im only a beginner, but I put a small amount of solder on the tip og the wire. Then I touch both the solderingpoint and the wire until they mix.

[Søndergård]

So, what are you guys final results with the MVDDC og MVDDQ mods? What did they before and after, and what amount af voltage do you think I can use for 24/7 on water?

[dejanh]

Stock volts on MVDDC/Q are 1.501V. If you OC, the maximum voltage tolerance for the Qimonda chips is 2.00V. They will fail at this voltage however if ran constantly. Because of the issues with OCP/OVP however you will not be able to run the core and memory volts very high together. Expect that if your core voltage is set anywhere between 1.35V - 1.37V you will not be able to get more than 1.65V to the memory without starting to experience the same issues as you did before. I'd say your most stable voltages will be about 1.37V core and about 1.6V memory.

I am personally finding that 4870s are proving to be very finicky for OCing.

[OnLine]

The memory controller (obviously inside the core) will start to crap out when using too high core speed & voltage. At core 850MHz @ 1.350-1.375V (whatever I used) it becomes really fluky and my card (HD4850) will no longer pass FurMark stability test. 1.400V core doesn't help, neither does 1.450V, neither does 1.500V .

However the card is perfectly bench & game stable in other bench app's & games. Now the question is;

How smart is it to squeeze the core for the last 50MHz when the card & its performance is already held back by the "low" clocked GDDR3 mem?
These will not run safely beyond 1200-1250MHz.

How smart is it to create an even bigger memory bottleneck?

However, getting the core speed up to max on the HD4870 is a different story. The GDDR5 memory allows this card to scale properly with core speed up to at least 1000MHz (I'd think).

//

I don't know, but I think I'll keep my HD4850 at ~800MHz core, 1150MHz mem (give or take 50MHz on both! ).

[aussie-revhead]

Hi guys , I just ran some tests on my new 4870x2 and fitted a 4870 for tri-fire but my pc will not boot with the 4870 installed , I get cmos error code shown on the lcd poster , has anyone else seen anything like this ? I have had this vid card in this pc before , and the pc will boot with either vid card on its own.

This vid card has been flashed with the modded bios , could this be upsetting things ? Or would they just dislike cf if that was the case ?

Any help would be greatly appreciated.

[xMrBunglex]

Hi guys , I just ran some tests on my new 4870x2 and fitted a 4870 for tri-fire but my pc will not boot with the 4870 installed , I get cmos error code shown on the lcd poster , has anyone else seen anything like this ? I have had this vid card in this pc before , and the pc will boot with either vid card on its own.

This vid card has been flashed with the modded bios , could this be upsetting things ? Or would they just dislike cf if that was the case ?

Any help would be greatly appreciated.

you don't mention what kind of power supply you have.

[dejanh]

...

However, getting the core speed up to max on the HD4870 is a different story. The GDDR5 memory allows this card to scale properly with core speed up to at least 1000MHz (I'd think).

...

This is only in theory. In practice there is no way that you will come even close to 1GHz core. 900MHz stable would be very lucky. Granted, one thing is true, the added mem bandwidth does kind of push one to try to push the core as high as possible.

I was just re-reading something and I noticed this...

Hi, at last I've voltmoded my 4870. Thirst of all GPU OC potential strictly depends on Memory clock. Here are some interesting results I've got:
1.283v (default), possible variants:
(GPU-MEM 3DMark Vantage GPU Score)
875-1200 9976

1.300v, possible variants:
880-1200 10005

1.305v, possible variants:
890-1150 10099
880-1200 10007

1.325v, possible variants:
895-1000 9839
890-1050 9983
885-1100 10015
875-1200 9976

1.350v, possible variants:
910-900 9827
905-1000 9967
895-1050 10004
885-1100 10020
880-1150 9998
870-1200 9914

What does it looks like? Right, it's no other then over current protection and 90% that it's located in BIOS (by the way you can check current in gpu-z 0.2.7). So here's Power Play II AMD has been talking about. Well AMD did a good job on failing our OC.
I hope in future versions of RBE we could heal this anti OC protection. Until it's done, no WR on this adapter would be possible. :/
By the way, it was certainly not because of the over hitting (using 1.35V):

You are saying you are not failing due to over heating at 1.35V, but you are running your GPU at 1.263V which is the default voltage (not 1.283V). Try actually running FurMark with 1.35V and high clocks. Otherwise, good observations, there is a definite link between maximum core and maximum memory

[MonsterMash]

Someone made a pencil vmod for the 4870?

[SNiiPE_DoGG]

Someone made a pencil vmod for the 4870?

no, its not possible. there is not resistor to pencil

[MonsterMash]

no, its not possible. there is not resistor to pencil

God damn'it, so the only way to make a vmod on a 4870 is soldering a vr?

[SNiiPE_DoGG]

God damn'it, so the only way to make a vmod on a 4870 is soldering a vr?

yes. for that matter it is a fairly easy voltmod the vddc point is very isolated. if your not good at soldering its hard though because the point is very small

[JeffLo]

hello i was wondering if anyone else is getting ATI Crossfire Disabled (crossfire available) in gpu-z, ive set it already in CCC to use overdrive and enable crossfire with a clock of 800/1100 for both cards, and when i test games and furmark and 3dmark06 i see first 4870 go to 800 core but the 2nd card is always at its idle 500/1100, only the first card goes to overdrive, i might be thinking that my crossfire is not enabled but when i use the overdrive core adjustments and test it it goes up to 800, anyone can shed light to this? thanks

[LuxZg]

kur¡,
Go here.
Look for "VDDC measure" in the pic...

OK, I've got a problem measuring, probably cos of my incompetence, but wanted to recheck with you guys.

I did use the above URL, and picture that is shown there. But I couldn't get any numbers from my multimeter, though it could be that I've missed the point somehow, even though I've tried 5-6x..

So let's take it step by step, as I don't use MM usually, and I've borrowed this one just for the occasion

1) I take multimeter and turn it on
2) I have a switch and a dial to set up the desired range
a) little switch that selects amps/ohms/and two types of voltages. One is V (that's DC right? or not?) and the other is V~ (AC?). I'm not certain which of the two is right (that's why I've included pictures, I hope they are shown right in post), as I'm not sure if GPU voltage is AC or DC.. Though I was just struck with the VDDC markings, but it could mean anything as I still don't know what MVDDQ means either except that it's some memory voltage So I guess it's DC, but tell me anyway, is it this one or this one ?
b) next I have a dial that's similar to this one ; it lets me select 2/20/200 for whatever I've selected on the switch (ohms, amps, volts). Should it be better to select 2V or 20V, since VGPU is <2V actually, I guess 2V is better and more precise, right?
3) I take those black and red umm "cables", and I put one on the VDDC measurement point on the VGA card, and other one where? As much as I know, it's just important that circle is closed, so I've just put the other side on the PC case.. It worked fine when I've tried to measure current on peripheral/molex plugs, showed 5V and 12V no problem.. But if VGPU is DC than what? And I guess than there is difference between using red or black one.. So a bit more info in here as well..

There are few things I could have missed, I'm no longer sure, but maybe I've switched to wrong voltage type (step 2-a). Also, maybe my PC case is not good for closing the circle when measuring VDDC on GPU (step 3), or i've just placed wrong red/black cable on the measurment point. Also, I could have missed the measurment point completely, so I didn't have good enough contact. Anyway, please, step-by-step instructions would be real nice, so I can do some measurments today or tomorrow when I should also have IR thermometer and power consumption meter, so I can check what are the effects of voltage/clock changes in BIOS, and how will it all affect stock cooler vs aftermarket cooler..

Thanks in advance

EDIT:
OK, solved. Not sure what I was doing yesterday, but today it works.

Btw, steps go as followed, just in case someone as confused as me tries later on
1) Take multimeter and turn it on
2a) select part of multimeter which shows
2b) with dial select 2V; in case you use same dial to select range and type, make sure, it says "2"
3) Take the red probe (cable) and put it on "VDDC measure" point marked in picture, while putting black probe to ground (meaning electrical ground, not on the floor -> black wires in molex/peripheral connector should be fine, just stick it into one of the two middle molex holes, so you have black on black, can't go wrong.. unless you're ME )

Interesting enough, I got 1.271V idle on 160/225 clocks, while 1.288V when overclocked to 790/1100 but still in 2D. Under load under overclock I get 1.305V measured. Is this ok? I don't have any mods yet on this card, neither BIOS or hardmods.. I'll go restart, and try again, as I haven't written it down right away..