700mhz wall on HD4850 is smashed.

[gurusan]

the smallest increment I have tried on the GPU is 5mhz and it seems to be fine...

[[XC] gomeler]

the smallest increment I have tried on the GPU is 5mhz and it seems to be fine...

Glad to hear. BIOS clocking is the only way to currently adjust above 700MHz? Not necessarily bad, just a lengthy process filled with reboots or risking Winflash

[gurusan]

Yup at the moment it's the only way. A bit annoying but I'm sure there will be driver based solution in the near future.

[[XC] gomeler]

K sounds good. Just read through the other thread, glad we can atleast BIOS flash, that's more important than driver clocking to me

[Caped Crusader]

900 mhz on an accelero S1 1.51v i have not tried for more.. almost 50k in 03 VERY bloated install..
http://www.hwbot.org/result.do?resultId=748596

900Mhz with such a hot chip?! That's a pretty amazing feat, dude

[DemonEyez]

I've uploaded my MSI bios and the modified Sapphire bios. Both are set to 710/1125MHz in 3D and 160/500MHz in 2D

http://rapidshare.com/files/12512715...-1125.rom.html

http://rapidshare.com/files/12512808...-1125.rom.html



Be sure to backup your original bios and have a automated restore floppy/usb disk at hand, should anything go wrong. Use at own risk
Make sure you have appropiate cooling!

900 mhz on an accelero S1 1.51v i have not tried for more.. almost 50k in 03 VERY bloated install..
http://www.hwbot.org/result.do?resultId=748596

Very,very nice!

[Caped Crusader]

@Caped Crusader
@eddieobscurant
@Battlestar
Concering those bios requests: I'll post rapid share links this afternoon. Right now I'm at work.
Important!, I use watercooling. I wouldn't recommend going above 700MHz with the stock cooler

Did some further testing last night, but it seems that 710MHz on the core is the max with stock voltage for me.
715MHz gives me artefacts in AtiTool after 1 minute or so.
But I encountered something else.
It seems that the speedsteps for the overclocking the memory becomes rather large after a certain threshold.

When I set 1125MHz in bios, GPU-Z reports 1125MHz being used correctly
When I set 1135MHz in bios, GPU-Z reports 1125MHz being used
When I set 1140MHz in bios, GPU-Z reports 1125MHz being used
When I set 1145MHz in bios, GPU-Z reports 1125MHz being used
I recall I don't have that problem with Overdrive. When I set 1140MHz in Overdrive, GPU reports 1140MHz.

What's that about? Does driver level overclocking allow for smaller steps concerning mem speeds?


*edit* found something about the changing steps in a MSI HD4850 review on Techpowerup.com:


http://www.techpowerup.com/reviews/MSI/HD_4850/24.html

Perhaps this pattern repeats itself at around 1100MHz

Oops, didn't realise you were using water!!

Thanks anyway!!

[Caped Crusader]

Guys, any luck changing fan settings? RBE doesn't allow (yet), AFAIK...

[BAGZZlash]

Guys, any luck changing fan settings? RBE doesn't allow (yet), AFAIK...

RBE v1.11 will. Check later today or tomorrow for it.

[[XC] gomeler]

RBE v1.11 will. Check later today or tomorrow for it.

Sweet and thanks for all the help

[Battlestar]

RBE v1.11 will. Check later today or tomorrow for it.

Dude, your a big help for us, keep us updated

[Miwo]

900MHz, very impressive James
It sounds almost like we may be able to hit the limit on air cooling using the 4850. All that extra vregs on the 4870 may make it better if you are using water and above, but I imagine the 4850 has to be pretty starved for bandwidth at 900MHz core.

[JamesBong420]

i know i can get more then 900 air... temps dont even hit 50c...stock clocks/volts load never broke 38c...

i stoped at 900 last night casue it was getting late. more later..

[ralf11]

4850 Gigabyte Bios.

Maybe change this values take effect.

[BAGZZlash]

4850 Gigabyte Bios.

Maybe change this values take effect.

What effect do you suppose this to have? It will only disable overdrive for this segment inside the BIOS is protected by a checksum. Because this sum's algorithm is unknown, we can't do anything about it. You're right, the values are what overdrive offers as a maximum for overclocking using overdrive, but if they get changed, overdrive won't work at all. At least, this was the case for 3xx0 cards.

[[XC] gomeler]

Could disabling overdrive enable rivatuner frequency adjustments by borking the driver controls on reverting clocks to the stock values? Perhaps it'll just bork the card BIOS? Worth a shot

[STaRGaZeR]

What effect do you suppose this to have? It will only disable overdrive for this segment inside the BIOS is protected by a checksum. Because this sum's algorithm is unknown, we can't do anything about it. You're right, the values are what overdrive offers as a maximum for overclocking using overdrive, but if they get changed, overdrive won't work at all. At least, this was the case for 3xx0 cards.

There were some 38x0 BIOS that had Overdrive up to 1500 for the core and it works flawlessly, I have one of them right now so it can be done. Problem is how

[Miwo]

i know i can get more then 900 air... temps dont even hit 50c...stock clocks/volts load never broke 38c...

i stoped at 900 last night casue it was getting late. more later..

Interesting, seems the heat output on the 4850 isnt that much greater than the 3870 then. I break just over 55C @ 1GHz on 1.55v with my 3870 with my Accelero S1.

James, do you hear any "squealing" noises from the capacitors/chokes on the 4850 @ 900MHz? I had this problem with my 3870 under load such as in ATITool artifact tester

[JamesBong420]

rivatuner just does not have the oc option(yet)...the little card u normally click on is not even there.

well all the way up to 875 there was no squealing. but at 900 there is a littlebit.. i have not added anything else besides some sinks.. some caps i shall be adding soon..

she is totaly 100percent stable.. played cod4(mp) for a while(an hour) at 900mhz not even a glitch... i just love how much smoother this thing is even at 700 mhz then my 3850 at 1039mhz..

now im stuck at work just wanting to play.. LOL

[Zucker2k]

There were some 38x0 BIOS that had Overdrive up to 1500 for the core and it works flawlessly, I have one of them right now so it can be done. Problem is how

Off topic: Javier, how's Madrid this afternoon? I bet it'll be one hell of a party city if you guys make it past the Russians huh? I'll be watching, should be an interesting game. No?

[Miwo]

awesome, good to know. let us know what caps you are going to add or replace the existing ones with
have you also done the vDDR mod? I can't decide if I want to go all out with the 4850 on some good air, or drop the extra $100 for the memory bandwidth of 4870 and better power regulation circuitry. I play on 1920x1080, which is only 8% more pixels than 1600x1200

[OCam]

Any Chance Some one could run some benches at 750 mhz ?(other than crysis!) trying to decide on single 4870 on air or vmodded 4850 on water

Edit: would a would a 120mm rad be enough for a chipset cooler and a 4850?

THX

[[XC] gomeler]

I can already bet that the 4870 will come out 10% ahead if not higher just from my experience with the 3850 vs 3870. Get a 4870 and clock it to 900MHz

[Caped Crusader]

rivatuner just does not have the oc option(yet)...the little card u normally click on is not even there.

well all the way up to 875 there was no squealing. but at 900 there is a littlebit.. i have not added anything else besides some sinks.. some caps i shall be adding soon..

she is totaly 100percent stable.. played cod4(mp) for a while(an hour) at 900mhz not even a glitch... i just love how much smoother this thing is even at 700 mhz then my 3850 at 1039mhz..

now im stuck at work just wanting to play.. LOL

What are you using to cool the damn thing?!

[Miwo]

Accelero S1 rev2 on 1.51v, he mentioned it above earlier. Its a great cooler that is often overlooked, very easy to add fans that will cover the full length of the card