4850 Soft-mod

[qwertyaas]

Question about soft-modding my 4850. The Voltage through BIOS is both for the Core and Memory correct?

My Visiontek has a stock voltage of 1.046 idle and 1.084 (not actual, checked from BIOS dump with RBE) at load and my max OC (CCC) is 700/1050. Bumping the memory to 1075 artifacts after a few minutes in ATITool (max load temp was 66c at 65% fan speed).

So bumping the voltage to 1.15/1.2 should give me a nice amount of headroom on the memory correct?

[xMrBunglex]

i didn't think raising the voltage through BIOS has any effect. that's the way it was with the 3K cards, at least. you could set it as high as you want but it didn't actually change anything.

[qwertyaas]

People that raised it said it did affect their OCs but only up to 1.2v. Anything above that can't be soft-modded.

[zanzabar]

if it helps go for it, the GPU should beable to do 1.2V without damaging them, if u have proper cooling

but the ram is qibmonda so dont push the voltage or frequency to high they tend to die

[AliG]

what's the pencil mod for the 4850? The vmod thread only shows where to solder

[qwertyaas]

Originally Posted by zanzabar

if it helps go for it, the GPU should beable to do 1.2V without damaging them, if u have proper cooling

but the ram is qibmonda so dont push the voltage or frequency to high they tend to die

Well, I don't have a multimeter so I won't really know if it does raise it (other than if it allows me a higher OC, but that's assuming it affects the memory as well).

[zanzabar]

the memory voltage is set in the hardware and dosnt change since the memory stays at 1 clock with the stock settings

[Heretic]

Originally Posted by AliG

what's the pencil mod for the 4850? The vmod thread only shows where to solder

See this post. You can ignore the text in green, that's for the regular mod, guru just reused the picture.

[qwertyaas]

Originally Posted by Heretic

See this post. You can ignore the text in green, that's for the regular mod, guru just reused the picture.

So just pencil in the blue area? Do you have a picture showing where to measure it penciling it in?

[jimmyz]

Originally Posted by qwertyaas

So just pencil in the blue area? Do you have a picture showing where to measure it penciling it in?

measure between the two points.* the default should be a little over 5k ohms lower the resistance to 4.86k or so and voltage should rise to around 1.26 loaded (3D)*, according to Gusrusan.

* always measure resistance with the card off. no power to it, preferably removed from the machine.

* use the VGPU measure points to confirm the amount of increase when you install and reboot. ( set the DMM to 2v range if yours has that) During boot (before windows) the voltage will be at the max the mod allows, windows will apply the 2D speed after desktop loads.

[qwertyaas]

Originally Posted by jimmyz

measure between the two points.* the default should be a little over 5k ohms lower the resistance to 4.86k or so and voltage should rise to around 1.26 loaded (3D)*, according to Gusrusan.

* always measure resistance with the card off. no power to it, preferably removed from the machine.

* use the VGPU measure points to confirm the amount of increase when you install and reboot. ( set the DMM to 2v range if yours has that) During boot (before windows) the voltage will be at the max the mod allows, windows will apply the 2D speed after desktop loads.

Thanks, will probably do the pencil mod once Rivatuner supports the 4800 series (and go to Radioshack and pick up a multimeter ).

[mouawad]

Originally Posted by xMrBunglex

i didn't think raising the voltage through BIOS has any effect. that's the way it was with the 3K cards, at least. you could set it as high as you want but it didn't actually change anything.

softmod gives 1.21v max tested with DMM - good enough for 720-740 maybe more with a good card.

[qwertyaas]

Originally Posted by mouawad

softmod gives 1.21v max tested with DMM - good enough for 720-740 maybe more with a good card.

Ah just around 740? Stock volts gets me to 700 without a hiccup, it's my damn memory that's the problem. 1050 is the highest I can get without artifacting (3rd card I tried as well, and all of them hit this wall).

[vortex240]

My saphire came with the 1.2v stock(measure at load with a digital multimeter)...not sure how since the bios dump showed the regular bios so with a flash I was able to get 770 on a stock cooler with fan at 60% and a 120mm fan blowing directly over it. Makes me think that these chips aren't binned at all. Accelero s1 is on the way.

[qwertyaas]

Originally Posted by vortex240

My saphire came with the 1.2v stock(measure at load with a digital multimeter)...not sure how since the bios dump showed the regular bios so with a flash I was able to get 770 on a stock cooler with fan at 60% and a 120mm fan blowing directly over it. Makes me think that these chips aren't binned at all. Accelero s1 is on the way.

Guess it's true that VT limits the volts going through the card then. A little modding should do the trick

[danbfree]

Originally Posted by vortex240

My saphire came with the 1.2v stock(measure at load with a digital multimeter)...not sure how since the bios dump showed the regular bios so with a flash I was able to get 770 on a stock cooler with fan at 60% and a 120mm fan blowing directly over it. Makes me think that these chips aren't binned at all. Accelero s1 is on the way.

OK, so I flashed my Visiontek to an Asus for fan control and now upped the volts to 1.25 (1.21 actual max under load they say) so what is the best way to OC past 700 at this point? Keep risking bad flashes by upping the clock there? Or use that new software that's out there? BTW, I also am running 60% fan speed with a 120mm blowing directly over it too.

As far as the OP, I don't think you can change the memory voltage and it's highly advisable not to... Then again it's easy for me to say since I hit 1133 out of the box with mine

[mouawad]

Originally Posted by qwertyaas

Ah just around 740? Stock volts gets me to 700 without a hiccup, it's my damn memory that's the problem. 1050 is the highest I can get without artifacting (3rd card I tried as well, and all of them hit this wall).

depends on what card you have, my 2 are powercolor 1.05v idle 1.15v load tested with DMM with stock bios so the soft mod helps a bit

wouldn't worry about the memory, i'd rather it stay alive than push it too far ...they're a bit fragile

Originally Posted by danbfree

As far as the OP, I don't think you can change the memory voltage and it's highly advisable not to... Then again it's easy for me to say since I hit 1133 out of the box with mine

you can pencil mod the mem as well - well pretty sure i've seen it ...not that i'd advise it for long term

[qwertyaas]

Did anyone test the performance difference higher memory actually gives (I would but mine doesn't OC that much) as opposed to the core.

I would assume core OC yields a much higher performance boost correct?

[AliG]

mem bandwidth really only makes a difference for max details at high resolutions, but the r600 showed that it didn't really need all that much bandwidth. And the 4870 performs at best case scenarios with max details 25% faster than the 4850, but in generally only 20% faster. Which means due to that the 4870 is clocked 20% faster, the core clock makes more of a difference

[Jakalwarrior]

so if I set it over 1.2 I can get 1.21? I can get 725-740 stable at stock voltage, but 750 will crash about halfway through a 3dmark06 run (no artifacts, just crash).

The memory voltage does change with powerstates though! I got stuck in the mid powerstate one time after a flash and my max OC went to 680/1040.

[danbfree]

Even with my voltage at 1.25 set in BIOS I am having a damn hard time getting above 700... Furmark just kicks it's butt even with my fan cranked up to 80%... oh well, still a DANG good card for the money and with the memory at 1133 that should help with any bottleneck too... now to get out of my A X2 @ 2.8GHz!

[TheKarmakazi]

Be very carefl not to corrupt the memory as many have already stated. And yes you will receive much more of a boost from increasing core clocks.

[danbfree]

Yeah, I never messed with any pencil mods for more voltage to memory, I just did BIOS for core... I backed down to 1.16 for 700MHz stable.

[ymer]

750 should not be hard to reach...

[Jakalwarrior]

Originally Posted by ymer

750 should not be hard to reach...

Sure not happening for me at 1.2vcore. Takes 760 to make artifacts but 750 will still blue screen or crash sometimes.