Calculating the key OC points on the 7800

any updates on the 512 oc bios?

Quote:

---

Originally Posted by HeavyH20

Hey guys. Haven't visited for a bit. Been running through the paces on the BFG 512's I have.

Some initial findings:

Default mem timings are in slot 3. The interesting thing is the timings are already tightened a tad from 1.1 ns GDDR3 spec. That is probably why the cards are rated to 1700 instead of the 1800 you would expect. Second, no delta on the new core, which is interesting in light of the faster DDR. You would think that the vertex cores would have even more work to keep up with fill from the DDR. Anyway, trying some BIOS mods to increase memory speed and also playing around with delta settings.

Back to the prior posts, I will be releasing a 20 MHz delta BIOS for the GT. My findings have shown this to be optimal on the GT cards. I will post that in a bit. Still doing a little assembly work on a couple of PC's.

The memory timing tweaks I adjusted do not affect memory OC. The best thing to help is heatsinks on the backside and a low speed 80 mm fan mounted on the side of the card. Keeps the memory a little cooler and the VR reg heatsink from getting too hot.

I should have a good OC BIOS for the 512 by Sunday evening. I will post some comparison numbers of before and after.

Hope these small changes see some even higher scores!

---

The rev4-500 BIOS is in this thread:

http://www.xtremesystems.org/forums/...ad.php?t=76667

An the modded 512 BIOS is in this thread:

http://www.xtremesystems.org/forums/...ad.php?t=81924

A note about the 512. nVidia did their homework on this card. There is not much to eak out of the card beyond the stock BIOS. Adding a delta did not help on either of the two test cards I had. And, tightening the memory beyond what nVidia had done works but may cause issues with any card that cannot get to 1800 stock. The one I use is the rev2-580 BIOS since it loosens the memory to Samsung spec so that 1800 is easily eclipsed. I was able to hit 1900 with this BIOS change versus the 1840 without.

Best bet is to call upon the services of volt mod masters like ViperJohn to work some magic on your card :D

To summarize findings for the GT:

1) use a 21 to 25 Mhz delta first. If your card can handle it, a 40 Mhz works well also. The default jump seems to be 13.5 MHz versus the GTX 27 MHz.

2) If you volt mod the memory, tightening the memory timings can add some significant performance.

3) Looks like the vootage change in the BIOS works for the GT. I do nothave a card to test, but many who have measured the change with a DMM report a true voltage increase.

May I ask which tools you folks are using to adjust the timings in your 7800 BIOSes? I have used NiBitor, but do not understand the coding system for the memory timings, nor are the timing sets labelled to correspond with any of nVidia's reference timings.


I have a 6600 GT here, referenced for 2.0ns memory, but equipped with 1.6ns memory, and a BIOS reference that likely reflects that in its timings.

Reading some of your results, it would appear to me, that slightly loosening the timings in my card's BIOS should allow for signifigantly higher memory frequencies.

My timings are like this now;
19
27
12
7
8
5
4

Can i change them to this, and then be able to clock them higher?

23
33
15
8
10
7
5

How do I change the memory timings for my EVGA 7800gtx 256mb?

Quote:

---

Originally Posted by bAdboLL

My timings are like this now;
19
27
12
7
8
5
4

Can i change them to this, and then be able to clock them higher?

23
33
15
8
10
7
5

---

I already gave you the answer before. Stop talking and just try it. Remember, the higher clock should only be the means to get a higher score, nothing else. If you need some help, just ask me.
Good luck

I had 19,27,12,7,8,5,4 before, now i tried to change to 12,21,7,5,8,4,2 which was the lowest i could use.

But there is absolutely 0% performance win, something is not right i belive.

Do i need to flash my card with the new values or is it enough to apply them in nibitor and run?
Should i maby get worse timings to be able to clock higher or what do you tihnk?..

Quote:

---

Originally Posted by bAdboLL

I had 19,27,12,7,8,5,4 before, now i tried to change to 12,21,7,5,8,4,2 which was the lowest i could use.

But there is absolutely 0% performance win, something is not right i belive.

Do i need to flash my card with the new values or is it enough to apply them in nibitor and run?
Should i maby get worse timings to be able to clock higher or what do you tihnk?..

---

Be glad that you did it wrong, your board would have been locked up with those silly timings.
Of course do you have to flash the changed Bios back.
I gave you two sets. I can guarantee that they work, so test them !!

He guys esspecially registrered to the forum so i can post en thank you HeavyH20 to share this great wisedom with us. Had some Atis the last few years, and had the great offer to swap my X850 XT Pl series against a MSI 7800GTX with a little extra payment from my site. Didnt have to think that long, and it was mine.

A good friend pointed me out this topic, and after reading it for some time i start looking what it had under the 'hood'/cooling, it only has the boxed fan and my cpu is only having a Zallman alcu fan on it. These magic steps in corespeeds is al you need to know for OCing this baby.

So with the boxed cooling and my cpu at 2,6GHz i got 540 on core and 1,36Ghz on mem, and that gives me a 19150 in 3d03 and even a 9277 in 3d05.
http://service.futuremark.com/compare?3dm05=1741347

Without any oc on my cpu, i managed to run a test in 03 on 554 core and 1400 mem (next core treshold in the line of special corespeeds) and it gave me 18,7K but it had that much artis i dont want to risk that again before i get better-than-boxed cooling, and hell this is all on asus A8n-E with a Pci-E MSI 7800GTX, while the same OS ran till last week my epox AGP mobo with an ATI card in it... :stick: whole the event viewer is full of errors, but it still goes fast like this.

Gonna install XP fresh this week, and I am going to see if these numbers can be brought any higher. I guess with some mem timing tweaking and a not cripple OS things can only get higher... :woot:

double woot edit: this time i had the pleasant offer to sell my MSI geforce and for only 25e (about 30$) extra i could buy a saphire x1800xt 512mb .. still a weekend left for playing with this one..

sorry if I missed it but do you have a bios for a new XFX 7800GT ?
Mine refuses to go over 475mhz core with rivatuner

How do I check bios info on the card


I did get this info from Rivatuner

$ffffffffff NVIDIA VGA BIOS information
$ffffffffff ----------------------------------------------------------------
$1100000000 Title : G70 P317 SKU 0002 VGA BIOS
$1100000002 Version : 5.70.02.13.09
$1100000100 BIT version : 1.00
$1100000200 Core clock : 275MHz
$1100000201 Memory clock : 700MHz
$1100010000 Performance level 0 : 275MHz/525MHz/1.20V/28%
$1100010001 Performance level 1 : 450MHz/525MHz/1.40V/43%
$1100020000 VID bitmask : 00000011b
$1100020100 Voltage level 0 : 1.20V, VID 00000000b
$1100020101 Voltage level 1 : 1.30V, VID 00000001b
$1100020102 Voltage level 2 : 1.40V, VID 00000010b
$1100030001 Core thermal compensation : 8°C
$1100030002 Core thermal threshold : 115°C
$1100030003 Ambient thermal threshold : 110°C
$1100030004 Thermal diode gain : 0.792°C
$1100030005 Thermal diode offset : 23.060°C

Quote:

---

Originally Posted by graham_h

sorry if I missed it but do you have a bios for a new XFX 7800GT ?
Mine refuses to go over 475mhz core with rivatuner

---

Are you talking about the XFX wit the black PCB?
If so, forget about somebody elses Bios, and read this thread
http://www.xtremesystems.org/forums/...ghlight=7800gt
from the beginning.
Bios modding to 1.5 volt is not possible, should be done by harware modding, and mem timing should be adjusted to the correct values with Nibitor.

I can not change timings in my 7800gt bios. When I save modded bios and open it again in NiBitor (2.6a), I still see original timings. Why?

Quote:

---

Originally Posted by davidian

I can not change timings in my 7800gt bios. When I save modded bios and open it again in NiBitor (2.6a), I still see original timings. Why?

---

Start Nibitor
1) Press "Tools" "Read Bios" and "Select Device" and on the pop up screen "OK" for the 7800GT that Nibitor has found.
2) On the start screen of Nibitor press again "Tools" but now "Read into Nibitor"
3) Goto "Timings" and press OK when it says "Very Risky"
4) Press "Autoselect Timingset". You are informed now which timingset applies for your memory.
5) Press "Detailed Timing" and you see now seven timing parameters with their values for the timingset that has been chosen.
6) Change those timings and press "Files" and "Save Bios" and give the Bios a name.

This is the new Bios to be flashed to your 7800GT.

If you start Nibitor again and press "Files" and "Read Bios" select your newly generated file, and voila there it is.

Dont work :(

I set timings like this screen:
http://img394.imageshack.us/img394/631/timing58nn.jpg

File > Save BIOS

And when I open this (saved) bios again, I have original timings, like here:

http://img394.imageshack.us/img394/6259/timing07mt.jpg

Quote:

---

Originally Posted by davidian

Dont work :(

I set timings like this screen:
http://img394.imageshack.us/img394/631/timing58nn.jpg

File > Save BIOS

And when I open this (saved) bios again, I have original timings, like here:

http://img394.imageshack.us/img394/6259/timing07mt.jpg

---

In the first picture I see timingset 5 and in the second timingset 0.
So you are looking at the wrong screen.

Hmm... I do it. By hand. I set Detailed timings like first screen. Saved bios. After open it again, Timingset is still 0 (zero), but Detailed Timings are good: 19-27-12-7-8-5-4.
Will it working fine?

Quote:

---

Originally Posted by davidian

Hmm... I do it. By hand. I set Detailed timings like first screen. Saved bios. After open it again, Timingset is still 0 (zero), but Detailed Timings are good: 19-27-12-7-8-5-4.
Will it working fine?

---

I have no idea what you are doing. Timingset 5 with the figures you showed are the standard Infineon 2ns Gddr3 values for the Green PCB XFX7800GT.
So without knowing the details of your board and your memory chips, how can anybody say if it will work.
To me it seems that you have changed nothing at all.

My 7800GT is manufactured by XpertVision. It's green PCB too.

Card:

http://img373.imageshack.us/img373/4...06674gk.th.jpg

Memory:

http://img373.imageshack.us/img373/2410/memorki3bw.jpg

Oryginal timings:

http://img352.imageshack.us/img352/6...ytuu1gq.th.jpg

And MODbios:

http://img500.imageshack.us/img500/9...ytuu8fy.th.jpg

Is it good?

Quote:

---

Originally Posted by davidian

My 7800GT is manufactured by XpertVision. It's green PCB too.

Card:

http://img373.imageshack.us/img373/4...06674gk.th.jpg

Memory:

http://img373.imageshack.us/img373/2410/memorki3bw.jpg

Oryginal timings:

http://img352.imageshack.us/img352/6...ytuu1gq.th.jpg

And MODbios:

http://img500.imageshack.us/img500/9...ytuu8fy.th.jpg

Is it good?

---

No it is not good.
The timingset to be used for your board is set 5.
All the other sets are not in use, no matter what you modify.

Attachment 42936
Here is my original bios (@1,5v). Could You try change timings, and send me modded bios to my email?

Quote:

---

Originally Posted by davidian

Attachment 42936
Here is my original bios (@1,5v). Could You try change timings, and send me modded bios to my email?

---

What do you want to change and why do you want to change.
You have Infineon chips, and timingset 5 is exactly what it should be for these chips, so ??

P.S. The Zip file you have added, is unreadable.

I want bios with timingset5, cause I cant do it (i have still timingset0 after modification bios)
Change .zip => .rar

Quote:

---

Originally Posted by davidian

I want bios with timingset5, cause I cant do it (i have still timingset0 after modification bios)
Change .zip => .rar

---

I inspected your BIOS, and as expected, your timingset5 is EXACTLY what it should be for your Infineon RAM.
So again my question: Why do you want to change a timing that is completely O.K.??
You have already changed the 3D mode to 1.5Volt. So since that is all there is to change, now flash this BIOS to your GPU.

Sorry, it was my mistake. I've got alredy completed bios.
Thanks for patient.

I have just water cooled my leadtek 7800gtx 256mb with a MCW55 and OCZ copper rammsinks. I would like to use the evga ko rev 4 bios but i have no clue on how to install that bios, so i was wondering if somebody could please tell me how to install it and also will this gve me much of a peformance gain in games like hl2, fear and quake 4.

Thanks