View Full Version : Looking for Texas meet ATI X850XT Vmods
Does anyone know and / or remember about the X850XT vmods that were done by an ATI engineer at the Texas meet - belive it was in 2004. There were a couple of pics posted here, but I don't remember what they weere for and where they were applied to... Any pointers would greatly be appretiated
persivore
12-02-2005, 11:30 AM
I think someone posted what the mods were in the Texas thread, but the post was deleted. I've read that there are some mods for the cards which are under NDA, so I don't know if anyone will be able to tell you about them. I haven't signed any NDA tho, so I will help you work out what the mods are if you like ;)
The only mods that I can think of which could have been done on the cards are Vdroop and Vref/Vtt. I think it is the Vdroop mod which is covered by the NDA, but I'm not sure.
There is a thread about Vdroop on the X800XT here (http://xtremesystems.org/forums/showthread.php?t=73549&highlight=Vdroop)
Thanks persivore - you willingness to help people is outstanding!!!
As much as I recall the vmod was done bascially on the opposite side of the core. I am experiencing a 0.02V droop - not sure if that is too bad or not..
I am just preparing a X850XT + CF for some CF benching and with both cards individually I am experiencing too hard sudden black screens running @ 1.74V loaded ~ -5C.
From my past experience with X850 cards I normall would be able to push both core and / or memory to a point where I could at least get some amount artifacting before the cards would crash - in those cases the runs are crystal clear and crashes are random and sometimes I can clock the card @ 710mhz - other times it duds @ 690mhz on the core.
Maybe it's the droop - just looking to find if there is another way to stablize the core.
Gautam
12-04-2005, 07:38 PM
Thanks for the assistance Persivore. Keeping a vmod under NDA is just about the most bogus thing I've ever heard.
I think someone posted what the mods were in the Texas thread, but the post was deleted. I've read that there are some mods for the cards which are under NDA, so I don't know if anyone will be able to tell you about them. I haven't signed any NDA tho, so I will help you work out what the mods are if you like ;)
The only mods that I can think of which could have been done on the cards are Vdroop and Vref/Vtt. I think it is the Vdroop mod which is covered by the NDA, but I'm not sure.
There is a thread about Vdroop on the X800XT here (http://xtremesystems.org/forums/showthread.php?t=73549&highlight=Vdroop)
What I am looking for is to disable temp monitoring. I am having problems with the card booting @ subzero temperatures.
When I boot into Windows @ ~ 0C I can lower the temps to about -65C and run the Marks - as soon as I reboot the card prvents the system from booting. I do not think that this is necessarly a cold bug - rather a bios protection.
I will look into different bios maybe something could be found there, but so far I have seen this problem with 3 seperate cards.
Maybe this is the omnious "JB" mod? CLearly several people have been able to run these cards at subzero/cascade/LN2 temps .
Another interesting thin g is this:
My first run was @ 1.64V and the core did an easy 840MHZ @ -31C loaded. When I raised the Vcore to 1.74 so far I have not been able to get sthe card stable at the same speed - actually not at all - lol due to the constant cold reboot problem.
persivore
12-12-2005, 12:38 PM
Can you tell me whats written on top of the 2 chips I've circled please. I think one should be the graphics BIOS chip, and hopefully the other one will be an LM63 (or something similar) for the temp monitoring :)
I'll look over the Vgpu regulators datasheet to see if I can work something definite out for a Vdroop mod :)
Highland3r
12-12-2005, 01:05 PM
As Per MSN convo Persivore
45AB
LM63
CIMA
Thats the lower of the 2 chips
THunDA
12-12-2005, 01:18 PM
I'll look over the Vgpu regulators datasheet to see if I can work something definite out for a Vdroop mod :)
I tend to get about a .02v droop when loaded too.. So I'd be interested to see what you come up with..
Thanks :toast:
SnipingWaste
12-12-2005, 01:22 PM
I was at the event but dont have any close pics of the cards.:(
http://pic15.picturetrail.com/VOL601/2766865/5546621/121647465.jpg
http://pic15.picturetrail.com/VOL601/2766865/5546621/121647429.jpg
runmc
12-12-2005, 01:34 PM
There was one mod that was done on the opposite side of the cards than the other mods and I kinda think there was a cap added. Here is a picture I took of the guy doing the mods.
http://www.teampuss.com/runmc/Lanparty/hardware/P1010029.jpg
http://www.teampuss.com/runmc/Lanparty/ATI%20mobo%20and%20card/DSC07807.jpg
I lightened the thumbnail a little.:D :D
persivore
12-12-2005, 01:34 PM
I've got an idea as to how to disable GPU temperature monitoring, but it will involve lifting 2 of the pins on the LM63 and connecting a transistor (or possibly a diode) between them. This should make the temperature sensor read the temperature of the diode instead of the GPU. I'll do some more reading and post something tomorrow :)
Edit: Thanks for the information everyone. I've been looking into the mods that were done at Texas for a few months now, but I haven't been able to find much information about them, and anything I do find usually leads to a dead end :(
Thanks so much everyone for the input!!! Brings me much closer to my 10K goal...
Persivore - not sure whether this makes any sense - but do you think it might be possible to rather add a pot - to raise the temperature that is being read? This way I could potentially raise the temp read under air under controlled constant temps by let's say 50C and have some sorts of temp monitoring. Not that I really need the temps - but I could be a nice gadget...
EDIT: Just thought about it - lol, don't think that would work - only the other way around...
I had seen one of the modded cards once - but didn't really pay any attention at the time.
I believe they where done to the chip with the following description:
4BAX TXM
CBT3257
the chip is to the left of the LM63 and has sixteen legs. This is different in what I can take out of runmc's pic - thanks runmc for those photos!!!
persivore
12-13-2005, 12:25 PM
The CBT3257 looks like its a multiplexer/demultiplexer. I'm not really sure what it could be used for on the card, but i'm thinking that it could possibly have something to do with the video output of the card.
I've got an LM63 from an old 9600XT, which I'm going try to connect to the SMbus to see what I can do to change the GPU temperature reading. I'll probably do this at the weekend, unless you need the mods before then :)
runmc
12-13-2005, 07:36 PM
I think they added a cap where I drew the oval. Or maybe some cards came with that cap and some did'nt.
It's food for thought.:)
cirthix
12-13-2005, 08:55 PM
I think they added a cap where I drew the oval. Or maybe some cards came with that cap and some did'nt.
It's food for thought.:)
my x800xl has a cap there
Grayskull
12-14-2005, 10:25 PM
"Ominous "JB" mod" --- what is that? :confused: And why is it so ominous? :)
What I am looking for is to disable temp monitoring. I am having problems with the card booting @ subzero temperatures.
When I boot into Windows @ ~ 0C I can lower the temps to about -65C and run the Marks - as soon as I reboot the card prvents the system from booting. I do not think that this is necessarly a cold bug - rather a bios protection.
I will look into different bios maybe something could be found there, but so far I have seen this problem with 3 seperate cards.
Maybe this is the omnious "JB" mod? CLearly several people have been able to run these cards at subzero/cascade/LN2 temps .
Another interesting thin g is this:
My first run was @ 1.64V and the core did an easy 840MHZ @ -31C loaded. When I raised the Vcore to 1.74 so far I have not been able to get sthe card stable at the same speed - actually not at all - lol due to the constant cold reboot problem.
HI Grayskull,
thanks again for answering my PMs to you!
I only heard from several people that there is/was a JB mod - no clue myself - lol. Maybe it's just a urban legend:p:
Gautam
12-15-2005, 09:16 PM
http://www.xtremesystems.org/forums/showpost.php?p=973548&postcount=103
Brand: Sapphire
Model: X850XT Platinum PCI-Express
Core OC: 750Mhz
Mem OC: 675MHz "Eisbach" timings
Core volts: 1.72V
Mem volts (VDD & VDDQ): 2.52V
Core cooling: P4 heatsink & 80mm Delta fan
Mem cooling: None
BIOS: Original
Temps: GPU: 46c idle & load... Mem: Unknow
Same "JB" mods that macci used for the cards in his Crossfire run ;)
http://service.futuremark.com/compare?3dm05=1053595
Mike- 840 easy :slobber:
http://www.xtremesystems.org/forums/showpost.php?p=973548&postcount=103
Mike- 840 easy :slobber:
Yep - kinda easy - lol
Like I said - ATI's 850 cards have been getting better and better over time. All the new cards clock insanely well!
I am sorry for all the GTO2 softmodders who are missing out on the real potential of the X850XTs !!! specailly on the current pricing on the real deal compared to the one legged dogs....jk
Gautam
12-15-2005, 10:18 PM
Does anyone else think this is a load of crap? How's it going to harm ATi at all to release these mods? Very few of us even bench X8xx's competitively these days. The card is last-gen. Someone who's going volt mod their card will do so even without these secret ones, so the warranty/RMA argument is moot. It seems like they're under NDA, in which case I can't blame you Grayskull for being unwilling to divulge them...but could you at least explain why ATi wants to keep a voltmod under NDA? I can understand ATi themselves being unwilling to let a volt mod go, but forcing people who don't work for ATi to keep secret? What the hell is the point?
Grayskull
12-15-2005, 10:26 PM
I think it's obvious why ATI needs to keep voltage mods out of the public domain. There are too many reasons that I won't even bother going into it, but they are all obvious.
Does anyone else think this is a load of crap? How's it going to harm ATi at all to release these mods? Very few of us even bench X8xx's competitively these days. The card is last-gen. Someone who's going volt mod their card will do so even without these secret ones, so the warranty/RMA argument is moot. It seems like they're under NDA, in which case I can't blame you Grayskull for being unwilling to divulge them...but could you at least explain why ATi wants to keep a voltmod under NDA? I can understand ATi themselves being unwilling to let a volt mod go, but forcing people who don't work for ATi to keep secret? What the hell is the point?
Gautam
12-16-2005, 10:48 AM
Oh yeah, then why aren't they pulling all the sites that show how to do the basic ones?
Kayin
12-16-2005, 12:22 PM
Basically put, for them to release volt mods is an endorsement of modifying your hardware AND an admission that they didn't build it the best they could. Damned if you do, Damned if you don't.
Same reason I can't break the PLLs on these Xpress OEM boards for customers...
Grayskull
12-18-2005, 06:02 PM
Show me one site where ATI is showing people how to do VMODS and I will have it taken down the next day.
Anyone is free to post what they like on how to do VMODS. Some are right, some aren't. As long as it's not from ATI, we're not concerned. The user accepts the results of whatever they do.
In this thread alone, there is mention of mods that are completely wrong. Like I said, the user accepts the results of whatever they do.
Oh yeah, then why aren't they pulling all the sites that show how to do the basic ones?
Gautam
12-19-2005, 12:14 PM
Alright Grayskull, point taken. Didn't mean to upset ya.