Any way to oc a 4850 beyond the CCC levels?

[dug777]

Tasty little oc even then, but I feel that it'd good for another 50mhz at least...

RAM only goes to 1128 from stock, not sure if ramsinks would help but in my experience they never do, I'm sure it's operating at it's binned speed in any event.

 

[tvdang7]

what brand you got? im jealous. to do 700-725 i have to do a bios flash to bump the voltage up on my Visiontek.

 

[dennilfloss]

Try using ATI Tray Tools?

 

[dug777]

Originally posted by: tvdang7
what brand you got? im jealous. to do 700-725 i have to do a bios flash to bump the voltage up on my Visiontek.

http://pics.bbzzdd.com/users/dug777/4850above.JPG

http://pics.bbzzdd.com/users/dug777/4850installed.JPG

Originally posted by: dennilfloss
Try using ATI Tray Tools?

Will try now

 

[ThaJollyMan]

Might try a lil cable management before you OC

 

[dug777]

Does ATT work under Vista64? I can't seem to get it working...

 

[error8]

Use Riva Tuner 2.11. I'm using it to overclock my 4870 on Vista64, with no problems at all.

 

[Concillian]

Seems whenever I touch my clocks even with overdrive 3dmark03 or 3dmark05 will bomb my computer.

I've had a clean run of 03 at 700 / 1100, but then 05 rebooted, then did 03 again and rebooted.

Dropped to 650 / 1020 and bombs away.

My card seems very touchy. rthdribl works great. Comp is still on the test bench, so I don't have anything real on it yet.

I'm thinking maybe the voltage regs aren't getting enough cooling? not sure. Core temps are good, between 50 and 55 at full load (MSI cooler, not the ATi cooler). I hope I don't need to rig a fan for the voltage reg. Maybe I need to go to an accelero and get a fan that will be blowing on the regulators. MSI has a little heatsink on the chips next to the regulators, but nothing actually on the regulators, and I suspect that's a problem.

http://www.newegg.com/Product/...eo%20Card%20-%20Retail

 

[error8]

Originally posted by: Concillian
Seems whenever I touch my clocks even with overdrive 3dmark03 or 3dmark05 will bomb my computer.

I've had a clean run of 03 at 700 / 1100, but then 05 rebooted, then did 03 again and rebooted.

Dropped to 650 / 1020 and bombs away.

My card seems very touchy. rthdribl works great. Comp is still on the test bench, so I don't have anything real on it yet.

I'm thinking maybe the voltage regs aren't getting enough cooling? not sure. Core temps are good, between 50 and 55 at full load (MSI cooler, not the ATi cooler). I hope I don't need to rig a fan for the voltage reg. Maybe I need to go to an accelero and get a fan that will be blowing on the regulators. MSI has a little heatsink on the chips next to the regulators, but nothing actually on the regulators, and I suspect that's a problem.

http://www.newegg.com/Product/...eo%20Card%20-%20Retail

No. The little heatsink you see there is on the voltage regulators. The problem is that even though the card has a heatsink on the vrms, there is practically no air flow over them, so that could make them loose stability. But this is a problem that mostly happens on the power hungry 4870. I find it a bit strange to see vrms overheat on the 4850, which suck "only" 110 W, opposed to 160W of it's bigger brother.Try getting a fan to blow some air over those, maybe it helps.

Anyway, I just sold my accelero to a friend and installed it on his 4850 and he gets 26 C idle and 39 C full load ( lowest temperatures I've ever seen on an air cooled graphics card until now). And this is with only one slow 120 mm fan strapped on the accelero.

 

[dug777]

Looks like 800 is the limit, prolly needs some more juice to go any further

I guess 800 isn't too bad, now I just need to get crysis working again so I can benchmark it.

 

[dennilfloss]

I too start getting the lone artifact or two at 800MHz core in ATITT. Happy to just use 790MHz. Not overclocking the DDR 5 as there's already tons of bandwidth at 900MHz.

 

[dug777]

Originally posted by: dennilfloss
I too start getting the lone artifact or two at 800MHz core in ATITT. Happy to just use 790MHz. Not overclocking the DDR 5 as there's already tons of bandwidth at 900MHz.

Mine seems fine at 800, but of course my RAM isn't quite the beast yours is.

This card must now be almost 100% memory bottlenecked

Using 3dmark05 my score increased by about 1000 between 625 and 800 (with a small boost from the RAM, now at 1028 from 993), but my q6600 is at stock so I don't know how CPU bottlenecked I am...

 

[Tempered81]

what happens when you set the core to 805 or 810mhz?

 

[dug777]

Originally posted by: jaredpace
what happens when you set the core to 805 or 810mhz?

The ati driver just crashed when I try to start a 3d app.

 

[error8]

Originally posted by: dug777

Originally posted by: jaredpace
what happens when you set the core to 805 or 810mhz?

The ati driver just crashed when I try to start a 3d app.

That is a sign that the GPU needs more juice for higher frequency. I guess you have one of those lucky 4850s, that can hit 900+ mhz on core, with a volt mod.

 

[OCChronic]

The best results are obtained by using RaBiT to modify the card's BIOS to adjust votages, clocks and fan speeds. It's tedious works and will take sometimes days to find the limits of your card but the results are excellent compared to software overclocking and are locked in. Yes it voids the warranty, but you can blind flash back if you have problems. There are plenty of write-ups detailing how to do this and how to recover if something goes wrong.

 

[error8]

Originally posted by: OCChronic
The best results are obtained by using RaBiT to modify the card's BIOS to adjust votages, clocks and fan speeds. It's tedious works and will take sometimes days to find the limits of your card but the results are excellent compared to software overclocking and are locked in. Yes it voids the warranty, but you can blind flash back if you have problems. There are plenty of write-ups detailing how to do this and how to recover if something goes wrong.

Why would one modify the bios for a simple overclock? Yes, you do that if you want to increase the voltage, but why would you do it to increase your clocks, when there are software around that can do that and will not void the warranty.

 

[Dazed and Confused]

Originally posted by: error8
Why would one modify the bios for a simple overclock? Yes, you do that if you want to increase the voltage, but why would you do it to increase your clocks, when there are software around that can do that and will not void the warranty.

We can tell you're not an overclocker if you have to ask that question. You may think you're an overclocker, but if you ask that question . . . you're not.

People used to ask me why I planed the chipset on my brand spanking new NF7-S R.2 when I got it years back. I know why, anyone that was a hardcore NF2 overclocker knows why but the people asking the question didn't know squat

TBH, if you have a beastly HD4850 Dug, I'd do the bios mod to get the extra voltage, theres no reason you shouldn't reward yourself with an HD4870 killer for all your effort to this point and the mod will only let you have what is rightfully yours

 

[Tempered81]

error8: the flash is to enable higher vgpu. Just like overclocking a cpu with higher vcore. sometimes software doesn't allow vgpu increases need to go thru bios.

for example people flash the rv770's with asus TOP bioses so when they install CCC sees more headroom for core/memory in overdrive & vgpu measures significantly higher in perf. 3d modes + beyond.

 

[Adam8281]

Using autotune with my Visiontek HD4850, I'm doing 690/1078. When OC'd like this, do you think it's best to set a manual fan speed, or leave it on auto?

 

[error8]

Originally posted by: jaredpace
error8: the flash is to enable higher vgpu. Just like overclocking a cpu with higher vcore. sometimes software doesn't allow vgpu increases need to go thru bios.

for example people flash the rv770's with asus TOP bioses so when they install CCC sees more headroom for core/memory in overdrive & vgpu measures significantly higher in perf. 3d modes + beyond.

Hmm, that's interesting. So, by flashing an Asus Top bios on my 4870, I could obtain higher voltage? I thought there are only hard volt mods for 4870 cards!?

 

[Tempered81]

Originally posted by: error8
I thought there are only hard volt mods for 4870 cards!?

That could be the case - no biosmod available. ill check the XS voltmod thread. Sometimes you can only hardmod for more volts to the gpu because the reference design sets a maximum voltage in a card's bios. Some cards can be voltmodded, some hardmodded, some both. There are bios modds for vgpu & vmem. and hardware mods too.

regardless, the bios flash to the ASUS TOP with the rv770's allows breaking the CCC overdrive limitation. Will edit this soon, brb.

edit: you can pencil-mod 4850's/4870's to above 1.45v Vgpu. Pencil mod first timer:
http://www.xtremesystems.org/f...howthread.php?t=204699

4870 ASUS TOP BIOS thread:
http://www.xtremesystems.org/f...howthread.php?t=196551

 

[firewolfsm]

The 4850 is almost completely bandwidth limited, even a core of 900 won't help too much if your memory is still at 1100.

 

[Tempered81]

firewolfsm, do you have a link to that russian/foreign page where they compared rv770 memory & core speeds to find the best combination of core vs. mem speeds? Its conclusion was that the cards gave more performance from memory overclocking.

 

[error8]

Originally posted by: jaredpace

Originally posted by: error8
I thought there are only hard volt mods for 4870 cards!?

That could be the case - no biosmod available. ill check the XS voltmod thread. Sometimes you can only hardmod for more volts to the gpu because the reference design sets a maximum voltage in a card's bios. Some cards can be voltmodded, some hardmodded, some both. There are bios modds for vgpu & vmem. and hardware mods too.

regardless, the bios flash to the ASUS TOP with the rv770's allows breaking the CCC overdrive limitation. Will edit this soon, brb.

edit: you can pencil-mod 4850's/4870's to above 1.45v Vgpu. Pencil mod first timer:
http://www.xtremesystems.org/f...howthread.php?t=204699

The pencil mod is only for 4850. There is only pot soldering for 4870 cards, sooo....that still takes me to my first post: there is no need to flash the bios when you are just overclocking. The CCC overdrive limitation is by passed easily with Riva Tuner.