8800GT bios for better overclocking! *test*

[nuttah]

is it really worth it?

YES

[XSS]

Where have it Tested ?

[krogen]

I think NVIDIA had a good reason to leave these Qimonda chips at 900MHz stock with tighter timings.

Here's what I did to my EVGA 8800GT SC (650/950/1625) with a HR-03 (non-GT edition) on top of it.

I first flashed my card to 1.1V plus I also changed the timings to Qimonda's reference design (see the OP's BIOS for the numbers). After a reboot I started upping the core frequency. At stock core voltage, I ended up at 730MHz, so I started from there. I got all the way up to 770MHz, that's 40MHz above what I previously got and 120MHz over the stock 8800GT SC clocks. Not too bad. I then lowered the core frequency to 760MHz (just to be completely safe) and started on the shader overclocking.

Before the 1.1 overvolt, I got to 1710MHz. This wasn't the max on stock voltage, I just didn't bother to see what it would max out. I started at that frequency and got all the way up to 1860MHz. Again, a pretty nice overclock.

Now, about the memory.

At this moment I was at 760MHz/Stock(950MHz)/1850MHz (lowered both the core and shader a little bit). No artifacts and it kept warm at 48C load after a 10 minute ATITool run (again, I have HR-03 on top of my card).

Before the voltage mod I got the memory to just 970MHz, anything above would give me artifacts (with the core at 730 and shader at 1710). So I started at 970MHz and kept going up by 10MHz every 5 minutes of ATITool running. I got to 1050MHz (!) but as I went up the temperature of the card and the case climbed steadily.

The voltage BIOS mod and changing the shader+core clock resulted in an insignificant increase in temperature (about 1C or so). But... Once I got to 1050MHz with the loosened up timings the temperature of the GPU rose up to 54C (that's 6C more than just with a shader+core overclock!). The temperature of the case also went up by about the same amount (!) (to about 42C (HOT!)).

This memory could be DDR2400 but it gets hot really, really fast. I'm sure with a better airflow through the case and some copper heatsinks (cheap aluminum right now) I could get to over 1100MHz, and probably everyone else with these timings.

is it really worth it?

I'm thinking your card is already at 1.1V since your clocks seem absolutely crazy for stock voltage (if they're at all stable, of course).

Check the voltage. If it turns out that you're at 1.1V you don't need to reflash the card. From what I've read this is the maximum these cards can do with a BIOS flash (according to ViperJohn @ ocforums)

[smsmasters]

Interesting krogen, what case do you have by the way? How exactly do I set relaxed ram timings using nibitor? Can I test the timings without flashing the BIOS to my card?

[krogen]

Interesting krogen, what case do you have by the way? I'll try and flash my 8800GT with the loose timings.

I have NZXT Apollo. A fairly decent case but it doesn't have a good airflow. Comes with one 120MM fan on the back (no more than 25CFM) and one 120MM on the window (pushes about the same amount of air). I have a 92MM Panaflo 45CFM on the HR-03 and underneath it there's a 40CFM slot cooler. Both push quite a lot of hot air outside of the case but I still never saw less than 30C in it on idle.

40C is just terrible and probably too hot for those Qimonda chips to operate properly.

How exactly do I set relaxed ram timings using nibitor? Can I test the timings without flashing the BIOS to my card?

Once you open a BIOS in Nibitor go to Timings tab and select Detailed Timings. There is an option right underneath it called "Test Timings" but I'm not exactly sure how well it works.

[A_Tiny_Chipmunk]

Im sorry, how do i cheak my voltage. I read most of this entire thread but i have forgotten.. (sisters wedding and all) so do i just save my bios with Nibitor? ive seen other ppl with the same card as mine and get like 720 on the core.. why would mine be so much higher? ill cheak my bios after you guys tell me how :P

[krogen]

The OP is wrong about the video RAM on the reference boards with HYB18H512321BF-10 chips. They're not 2400. They're actually 2000. I think the OP looked at HYB18H512321BF-8.

Take a look:
http://www.qimonda.com/promopages/in...AM%2FGDDR3%3A1

Im sorry, how do i cheak my voltage. I read most of this entire thread but i have forgotten.. (sisters wedding and all) so do i just save my bios with Nibitor? ive seen other ppl with the same card as mine and get like 720 on the core.. why would mine be so much higher? ill cheak my bios after you guys tell me how :P

Are you sure your clocks are stable? They may appear stable when playing but that isn't necessarily the case. Do you use ATITool to check the stability?

You might either have a really good card or it might have came with 1.1V out of the factory.

[alexio]

The OP is wrong about the video RAM on the reference boards with HYB18H512321BF-10 chips. They're not 2400. They're actually 2000. I think the OP looked at HYB18H512321BF-8.

I intentionally used the DDR2400 (0.8ns) timings to see if changing the timings has any effect on memory overclocking at all. I though I made this clear in the first post.

[STEvil]

Has anyone done some benches to see what changing the timings has effects on?

[A_Tiny_Chipmunk]

Yes i used ATI tool, no artifacts. Stable for like 2 hours. it sits at the max temp (like 45) for about 1:58 mins lol. so im pretty sure its stable. yes all stock volts.

How do i test if its 1.1v already?

[smsmasters]

I intentionally used the DDR2400 (0.8ns) timings to see if changing the timings has any effect on memory overclocking at all. I though I made this clear in the first post.

Can you please tell me how exactly to edit my own BIOS with the 0.8ns timings in Nibitor? Many thanks, I'm not sure which timings subset to edit.

[mrQQ]

gosh, has anyone who's pushing the card to the limits actually tried to see if it gives any benefit whatsoever?

[krogen]

I intentionally used the DDR2400 (0.8ns) timings to see if changing the timings has any effect on memory overclocking at all. I though I made this clear in the first post.

Ooops. Sorry.

I don't think I'm the only one who misinterpreted your post though.

First few posts:

if they are 2400 why can't i go past 2100 roughly LOL

Maybe he's got a card with different ICs, and not the "suggested" 1ns modules from Samsung/Hynix.

[alexio]

Can you please tell me how exactly to edit my own BIOS with the 0.8ns timings in Nibitor? Many thanks, I'm not sure which timings subset to edit.

Change the timings under "detailed timings" to this:


After this save the bios and it's ready for use

[taowulf]

I believe alexio's bios settings are what i loaded up(no access to that PC right now) and I was able to improve my overclock from a fairly respectable 720Mhz core to 792Mhz core, 1998Mhz shader, 2016DDR Mem. 799Mhzx core or above 2K shader locked up on loading any 3D app.

3Dmark06 link - 14,755

http://service.futuremark.com/compare?3dm06=4333775

Starting point was around 11K at stock CPU and Vid card speeds (it is a 8800GT SC, which is what, 650/1600/1800 or something)

I've not tried to tweak the BIOS further, as my 680i died the day before Xmas.

[smsmasters]

Change the timings under "detailed timings" to this:


After this save the bios and it's ready for use

Many thanks, how about timingset 1, 2 ,3, 4 etc? What are they for and which one does the 8800GT use?

[alexio]

Many thanks, how about timingset 1, 2 ,3, 4 etc? What are they for and which one does the 8800GT use?

They show the same timings in HEX code. The sets are predefined. You can choose to read the current timingset with the "autoselect timingset" button but I'm not sure how accurate this is.

It's best to manually edit the timings in the fashion the picture shows

[wedfighter]

here's my POV 8800GT EXO..stock cooling no vmod
it's already 1.1v on BIOS



BIOS



Checked with DMM
vgpu @ idle 1.13v
vgpu @ load 1.16v

wanna try to loosen timing

[smsmasters]

I edited my BIOS with the looser timings, thanks alexio. I can now bench with the RAM at 1100MHz, before it would freeze.

[giorgos th.]

so,how`s mhz vs timings performance?
did you gain anything?

[smsmasters]

47.825
nvidia 8800gt 512mb @ 756/1100/1836
Windows XP 32bit
intel e6600 @ 3600mhz

[smsmasters]

so,how`s mhz vs timings performance?
did you gain anything?

The looser ram timings allowed me to bench at 1100MHz, whereas before it would freeze. That's about it really.

[giorgos th.]

did you notice better results with 1100mhz and looser timings?

[smsmasters]

Ok, my RAM is not stable at 1100MHz, it crashed in the CS:S video stress test. I'll test if 1053MHz is stable. I can run the crysis bench at 1100MHz though but it gives me very little increase in fps.

[smsmasters]

I can confirm, before loosening the timings, I could not get the RAM stable above 950MHz, now it is stable at 1053MHz.