ATI 5850/5870 voltmod thread

[CL3P20]

1. changing the resistor should bring increased vMEM to max safe limit.. manufacturer did not realize gains past new voltage limit- so my guess is its not going to benefit.. VR should do just fine though.
2. OCP overall- as stated..overall GPUv OCP control/disable... OCP phase = OCP limit per phase - must for high vcore
3. vGPU is only VID, by default.. can still bump with software though, it just sets new default per VID mod.

hope that helps.

*vDDCI mod is must too... folks not seeing gains beyond ~1.25v though. I have not been able to monitor vDDCI for droop under load yet, but suspect capping might boost FPS in the same fashion PLL mod/cap works for 470/480

[T_M]

Special AB?

[Barr3l Rid3r]

ok, I ve maded the OCP in my reference 5850 and it's the same for the 5870, but it's in the back of the card.

It also gave me an 0,03v increment. But I got no better OC results, no matter what I can't pass 980mhz

Probably I need VDDCi? My temps don't go over 65C gpu even when at 1.35v and vrm tems are cooler then 80C running furmark...

my card sux... anyway lets unless share it.

[T_M]

Just want to check, are you measuring with vdimm to ensure your set voltages are working?

[Barr3l Rid3r]

Just want to check, are you measuring with vdimm to ensure your set voltages are working?

vdimm? I think u mean dmm? (digital multimeter) I checked and it works, but no gains can be attained after 1.32v, but temperatures are low and under control, thas why I don't now why.

[T_M]

yeah sorry slip of the tongue

Last night i tested AB 1.41 Extreme but no luck being able to change volts.
Pretty convinced 1.6 Extreme is required. Anyone got it?

[Hondacity]

maybe this?

http://downloads.guru3d.com/Afterbur...load-2559.html

[CL3P20]

i have 1.5xb as well if the 1.6b doesnt work..should though

[DEVIL K-ce]

yeah sorry slip of the tongue

Last night i tested AB 1.41 Extreme but no luck being able to change volts.
Pretty convinced 1.6 Extreme is required. Anyone got it?

Try this one 1.6x

http://www.speedyshare.com/files/229...60x-Beta-6.exe

[T_M]

Thanks boys, havent tested yet but im sure thats what im looking for.

[T_M]

the 1.60x-beta6 is not an extreme version voltage max still 1.35V and clocks have max too.

[quake6]

Try one that I sent you

[DEVIL K-ce]

the 1.60x-beta6 is not an extreme version voltage max still 1.35V and clocks have max too.

Hmm strange, with 5850 referent design I have up to 1.55v for gpu, also the same with 1.51X AB. Maybe Your vga bios is problem ?

[nickless]

the 1.60x-beta6 is not an extreme version voltage max still 1.35V and clocks have max too.

Try in this and this way, it works on my CF Sapphire 5850:

[Hondacity]

the 1.60x-beta6 is not an extreme version voltage max still 1.35V and clocks have max too.

did you go to settings and unlock the voltage limit? its an option you have to enable

[T_M]

Yes i did that.
Anyhow, 1.51x (which was optimised for 5870) gives what i need.
I believe 1.60x was optimised for 480.

[T_M]

My lightning is now easily flying at 1340/1275 with only vgpu mod (thanks Hipro!) and can bench as low as -170C without problem (didnt test any lower).

[EvoCarlos]

My lightning is now easily flying at 1340/1275 with only vgpu mod (thanks Hipro!) and can bench as low as -170C without problem (didnt test any lower).

i thouhgt the lightning's were good

but it seams my ref card is also good 1350/1310 no cb problems with ram or core had had filled the pot to the top and -186 was the coldest my meter would read

[T_M]

vGPU, and both OCPs using VRs

[EvoCarlos]

nice t_m
i also managed a bit more with my ref card
1411mhz


the only problem was after 3hours the mem cold buged and would not pass 1200 i need to find a way to stop the ram bugging

[CL3P20]

..can keep the CB away..shhh :p

[T_M]

oooooh, do share

[Oliver]

very tight card you got prepped there man.

Beg up

[CL3P20]

oooooh, do share

i did...but here it is again in less obvious form

http://www.reptilebasics.com/flexwatt-heat-tape/

I havent got a chance to use it yet..but its got ftw written all over it. [low power TEC should work good too]

[Jimbo Mahoney]

I have a Sapphire 5830 that I hardmodded (vGPU only) but the core runs out of steam unusually quickly and more voltage doesn't help.

My fear is that it's simply hitting a wall and there's nothing I can do about it, but I want to explore the other possibilities (e.g. OCP, VR cooling etc.) Here's the details:

On stock voltage (~1.15V) and cooling, the core can do 1030Mhz.

vGPU mod (~1.25V) and watercooling (core only, 38'C full load), it rapidly hits a wall at around 1150Mhz (i.e. system locks up / screen goes blank).

I've taken the voltage to 1.35V with no improvement.

Having checked the 58xx overclocking thread, it does seem that most 5850s and 5870s also crap out at about 1100Mhz until using very high voltages and extreme (sub-ambient) cooling, reinforcing my feeling that this is a chip limitation as opposed to cooling / OCP issue.

Any thoughts?

In addition, has anyone found any improvement from vMem mod and/or memory cooling? (I can't find any info on this yet - still looking).

Thanks.