aldamon, I already wrote my observations of the 7800GT a few posts back.. take a look :)
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aldamon, I already wrote my observations of the 7800GT a few posts back.. take a look :)
Why did you start so low? HeavyH20's chart starts at 419 and yours finishes at 428. Surely your GT can go higher than 428.
Well, I experimented with ATI Tool and RivaTuner last night and determined there is indeed a key 7800GT OC point at 473. At 473, the ROP and Shader jump to 486. Unfortunately, my core couldn't handle a 40 MHz delta at 473, so I backed the base speed down until the artifacts were eliminated. Dropping 8 Mhz down to 465 did the trick. This told me my max geo speed is 504. So, using that knowledge, I modified my BIOS with a 32 MHz geo delta, which allows me to hit 473 base and 486 shader/ROP, while still limiting my geo core to 504. I'm not sure why setting the delta to 32 Mhz results in only a 31 MHz bump, but it does.
Tonight I'm going to see if I can reach the next ROP/shader speed bump while keeping my geo core at a max of 504 with a custom delta. The closer I get to a 504 base speed, the smaller my custom delta is going to get. The highest combination of shader/ROP/geo should give me the best performance. I think the folks who claim to have better performance overclocked without the delta have surpassed the next key OC point (500ish) and have boosted their Shader/ROP speeds. It would take a base clock in the high 490s to 500s without a delta to do this.
8159:
http://service.futuremark.com/compare?3dm05=1359710
473 MHz base / 1240 MHz mem / 504 MHz Geo / 486 MHz ROP / 486 MHz Shader
1.51V VGPU (Modded BIOS)
2.16V VMEM (Pencil. Is this the best I can do with a pencil?)
Custom 32 MHz Geo Delta
Free Air Cooling Mod: http://www.xtremesystems.org/forums/...ad.php?t=69513
Sorry for the noob question but are the 7800GTs different than the 7800GTXs, in that voltage to the gpu can be increased via the bios?
no voltage increase via bios.. But the GT i believe can be volt modded with just a pencil.
Yes Voltage increase via BIOS, at least you can for the core.
i have an EVGA 7800 GT (non CO version). I bought the card right when the 7800 GT's came out. My EVGA 7800 GT came with the Rev.1 BIOS (with the geometric delta clock of 40mhz) but i was artifacting so i switched to the Rev.2 BIOS.
my card is only able to get to 462mhz on the core (sad) but it bumps it up to 464. I'm a little confused here because reading through this thread, having a lower core clock with a geometric clock would perform better than a higher clock without a geometric clock.
well, i modified my BIOS so the core was only at 419 with a geometric clock at 45mhz (making it 464) but my 3dmark05 score was 200 points lower compared to my card at 462 without a geometric delta clock.
i'm guessing im looking at this the wrong way... can someone tell me what the best way to modify my BIOS? ie the geometric clock and my main core clock etc.
Some key differences between the GT and GTX.
1. According to the results I have seen, the ROP appears to bump at 13.5 MHz points versus the 27 MHz on the GTX.
2. Most GT cards do not have a delta and appear not to gain as much with this in place. Since the GTX uses a 1.5 root oscillation multiplier, extrapolating that result to the GT would be 20 Mhz.
3. The ratio of physics (vertex) to fill (shader/ROP) is 1 to 3 on the GTX. On the GT, it is 1 to 2.85. Also, fill is channeled through the memory, which is also slower on the GT than the GTX. So, there should be less of a bump required on the vertex component to match fill rates.
Things to try:
Use a 20 MHz delta, and see if your results improve. 40 Mhz is too much of a delta for the GT to see any real gains over no delta.
Is there anyone willing to test this and report back?
Only if you are not already using 1.4V. While some editor versions allow you to select 1.5V, it is not physically available so getting the BIOS to ask for voltage that is not there has no net effect.Quote:
Originally Posted by K404
ok, so since my MAX core can only handle 464, you want me to try a 20mhz delta, so i should try 444 + a 20mhz delta = 464 and i should get better performance?Quote:
Originally Posted by HeavyH20
i find that if you modify the same BIOS, you don't have to re-install the drivers everytime so its pretty easy for me to experiment with different settings.
i have an XFX GTX, the lowest version..comes clocked at 450/1.25ghz...so far, i can only get about 512/1.36. This seems pretty low compared to others OCs...and im cooling it with a maze4..so the core temp, according to the driver, is 31c...any one got any ideas as to how to crank a bit more out of this puppy?
edit: nm.
The max my BFG 7800GTX SLI's can handle is 490/1.38 with coolbits. They are watercooled, and run at about 52c on a load, but 1 of the cards still artifacts on anything higher than that. I really want to try h20's 500/1350 BIOS out, but im pretty sure it will artifact on me. Is there anything i can do?
Ive got my BFG 7800GT Volt Modded to 585/1300 with no
artifacts. Temps idle at 30oC and max at 340C with Water cooling.
http://img417.imageshack.us/my.php?i...scf05890jk.jpg
:banana:
Im hitting 19600Points in 3Dmark :03
www.4qman.com
S12 600w SLI PSU
MSI K8N Platinum *Volt Modded*
3800X2 @ 2.68Ghz
OCZ TCCD @ DDR536 2.5-3-3-6 T1
BFG 7800GT @ 570/1320 *Volt Modded*
*WATER COOLED*
http://img44.imageshack.us/my.php?image=dscf07611ae.jpg
http://img44.imageshack.us/my.php?image=dscf07238cw.jpg
nice
this is a very noobish question, but what is the molex for? Extra power or something?
Quote:
Originally Posted by 4Qman
wow excellent clock speeds m8 :slobber: :toast:
i have one of those cards, these voltmods are looking seriously tempting :stick:
Yes, the PCI-Express slot can't give enough juice.Quote:
Originally Posted by don_vercetti
so it needs a molex, as well as the PCI-E slot + the PCI-E power connector?? I find that hard to believe...Quote:
Originally Posted by alexio
why?Quote:
I find that hard to believe...
PCI-E slot gives 75w at least, and the total power consumption of a 7800gt can't be much over 120w or so, even overclocked. I'm sure the PCI-E connector can deliver 50+w so there is no need for a molex.
Also, the molex has no grounding cable, so i really do doubt it is for power.
In fact, i'm stupid - those are the vddr and vgpu measuring points, so i guess the molex is there to make it easier to measure those two - right?
:slapass: :stick:
i am slow.
Thats correct Don,
The Molex is to meause the VGPU and Ram Vddr "conected to the measuing points. Its alot easyer than trying to measue them with the Card in the case.
I was planning on fitting a switch to turn the mod on and off but
i decided it could cause some damage if i caught the wires and removed a resistor.
Ive not really had much time to play with the mod but i know im about 400points short of hitting the 10k mark with 3dMark 05. Altho i doubt ill hit it.
you can but try. Just needs one cold night.
there a tutorial around for vmodding the 7800gtx?
Here is the link to the 7800 GTX volt mod thread.
http://www.xtremesystems.org/forums/...ad.php?t=67494
That stuff is like greek to meQuote:
Originally Posted by HeavyH20