XFX 7900 being sneaky with delta clocks

Hmmm XFX might not be clocked as high in real 3D mode http://forums.guru3d.com/showpost.ph...postcount=1172 ?

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Originally Posted by glenboy

i have been looking into the bioses of a few of the 7900 series cards and the 7900gts, all the gts i have seen run at 1.2 volt in the bios where as gtx runs at 1.4 so i am sure when the bios is modded to 1.4 on the gts with adequate cooling of course it should in theory be able to reach a similar level on the core as gtx, the weirdest thing i saw is on the delta clocks in the cards bios my msi 7900gtx has a 50mhz value on all 3 vid values whereas the 7900gt by xfx has 0 on all values on the delta clocks and the xfx 7900gtx xxx has 15mhz value on the delta clock of the core, whereas the msi 7900gtx has delta clock of 50mhz on the core, i wonder if this is done to give them a higher core clock value, i don't know, i'd be interested to know what difference the delta clock values make

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for those unfamiliar with delta clock or geometric clock on 7800GTX series they had a 40mhz delta clock so for example BFG 7800GTX rated 460/1300 in 3d mode would be 500/1300 and drop back to 460/1300 in 2d mode.

With 7900GTX, MSI has 50mhz delta while XFX 7900GTX XXX has a 15mhz delta.

If MSI 7900GTX stock core is 650mhz then 3d = 700
If XFX 7900GTX XXX stock core is 675-690mhz then 3d = 690-705mhz

so in 3d mode it might end up the same clocks!!!!!

Interesting to see what other 7900GTX brands have for a delta clock value!

interesting

yeah wonder if eVGA 7900GTX SC locking issues might be due to the delta value ??? 690mhz + 50mhz = 740mhz on core if they had 50mhz as delta like MSI

so in fact these higher clocked cards arent any better than the others because theres a less or no delta instead of the 40 or 50 whatever... thats sucks all promotion....

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Originally Posted by eva2000

for those unfamiliar with delta clock or geometric clock on 7800GTX series they had a 40mhz delta clock so for example BFG 7800GTX rated 460/1300 in 3d mode would be 500/1300 and drop back to 460/1300 in 2d mode.

With 7900GTX, MSI has 50mhz delta while XFX 7900GTX XXX has a 15mhz delta.

If MSI 7900GTX stock core is 650mhz then 3d = 700
If XFX 7900GTX XXX stock core is 675-690mhz then 3d = 690-705mhz

so in 3d mode it might end up the same clocks!!!!!

Interesting to see what other 7900GTX brands have for a delta clock value!

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that's not actually what the delta clock is.

basically 7 series cards have 4 different clocks, geometric core clock, shader core clock, ROP core clock and memory clock.

the shader and ROP run in 3d at whatever you clock them to in coolbits etc. (though they only have speedbumps every 27mhz.)

the geometric core clock is the one thats affected by the delta, it's basically the above clocks + the delta value. the geometric core clock doesnt clock in 27 mhz steps though, which is why you will see a minor increase in speeds even without going up in 27mhz steps. :)

EVA2000 so why the high scores in 3dmark????

for example:
if it was like you say so a XFX 7900GT cloked at 565/1800 the real cloks are (= +- 550/1800 )

and other 7900GT card like MSI at 550/1800 n fact its same as a XFX at 565/1800 and if is like that why if you run a 3dmark 2005 with MSI at 550/1800 you only get +- 9800marks and with a XFX at 565/1800
you get 10020maks ???


i think thats make no sense

How do you check the delta on your card? I'd be interesed to see what mine is.

~Mike

The ROP/Shader clocks are what matter the most, that's why.

I know on my 78GTX, my core could do either 600+50, 625+25 or 650+0 and it was all equally stable....but any higher on the geometry clock and it became unstable. This wasn't a big deal though as the ROP/Shader clocks are the most important, so I ran 650+0 for the highest scores. I never tried a negative delta (idk if it's even possible).

IMO...the shader clocks are what sell the card, the geom clocks are just gravy if you can get it to scale well :fact:

I just checked mine in Nibitor.

my stock speed is 650/1600 with a 50mhz delta
The EVGA runs 690/1760 with a 50mhz delta aswell.

Some information for you, I hope it helps.

~Mike

what version of nibitor your using???

2.7

in nibitor mine say geometric delta clock ---- 0

GTs are supposed to have a 0-13MHz delta and GTXs are supposed to have a 0-50MHz delta, depending on the brand and stock speeds.

XFX 7900GT Extreme stok speeds (520/1500) ---Geometric delta = 0

This maybe why Im only able to do 697 tops. thats about 747 after the delta. I wonder if lowering it to 0 would yield any benefits.

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Originally Posted by arisythila

This maybe why Im only able to do 697 tops. thats about 747 after the delta. I wonder if lowering it to 0 would yield any benefits.

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Try lowering it to 0....if it still doesn't respond, your ROP/Shader clocks are what are limiting you, so raise the delta (experiment with this)

@eva2000 ...can you give the link of the full thread over guru3d???:D

Kunaak's going to be ALL over this :D :D :D

Perkam

Let me know if I understand this: You can control the amount of the 3D bump for Nvidia cards? So some of the OC factory cards are really not that OC'ed when in 3D? I am thinking about getting a 7900gtx and with this info it makes me wonder if it's worth getting the ones that are OC'ed.

what are u all talking bout whats the REAL specs with deltas with 7900GT/GTX?

cant be that there are variable deltas between 0-50mhz must be a spec?!

lol

EDIT. here on the 7800GTX 256Mb (stock 430/1200mhz version) its 3D +50delta, 3D-throttling +45delta and 2D +0 delta
there must be such fixed specs 4 the 79GT/GTX

eVGA/XFX/BFG etc. control the clocks, including the delta. Each part number has a different set of clocks and deltas.

nV recommends 650+50 and 450+12.

It is absolutely worth getting the OC'd ones.

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Originally Posted by Vapor

eVGA/XFX/BFG etc. control the clocks, including the delta. Each part number has a different set of clocks and deltas.

nV recommends 650+50 and 450+12.

It is absolutely worth getting the OC'd ones.

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ok, thx so its 700/462 3D delta

yeah with air its sure worth but with real xtreme cooling and ocing it really doesnt matter as far as i know.

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Originally Posted by lawrywild

that's not actually what the delta clock is.

basically 7 series cards have 4 different clocks, geometric core clock, shader core clock, ROP core clock and memory clock.

the shader and ROP run in 3d at whatever you clock them to in coolbits etc. (though they only have speedbumps every 27mhz.)

the geometric core clock is the one thats affected by the delta, it's basically the above clocks + the delta value. the geometric core clock doesnt clock in 27 mhz steps though, which is why you will see a minor increase in speeds even without going up in 27mhz steps. :)

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Good summation.

The first guy at guru3d said he had a delta on "all 3 vid values" which is impossible as a delta means a change from the standard.

core\geometry+15\rops

would be a delta of 15, having all at +50Mhz would mean a delta of zero.

Can anyone actually tell me what he is saying when he says :-

"the weirdest thing i saw is on the delta clocks in the cards bios my msi 7900gtx has a 50mhz value on all 3 vid values whereas the 7900gt by xfx has 0 on all values on the delta clocks and the xfx 7900gtx xxx has 15mhz value on the delta clock of the core"

in plain English ?

Why do I get the feeling Unwinder is going to rip him a new large one ? :D

Regards

Andy

possibly he means in 3d, throttled, and 2d modes?

Basically those pre overclocked 7900GT all have their GDC disabled. That's why they can be factory defaulted to such high frequency.

My BFG 7900GT OC has 20MHz GDC.

this would indeed be very misleading, if companies were using extremely low deltas... to gain "higher" clock speeds, that really aren't all that high.

the tricky thing is, delta, really only has a small impact on actual performance on the 7800 and 7900 cards... so it would be very hard to say one card was faster then another, if the only differences was deltas.

if however, the deltas are so vastly different, like from 690/15 to 650/50 then it would be very interesting the see the actual difference in a side by side comparison by simply taking the same card, flashing it with one bios, then another, and so on... to get side by side performance differences.

it might be very interesting for people to see, that thier 690 mhz cores, really aren't any faster then a 650 mhz core, assuming the mem clock was the same between each bios to remain consistant.

by the way, you can check the Delta of a card, with Rivatuner, in the diagnostic report.
unfortunatly, rivatuner at the moment doesn't support 7900's or the 8420 drivers yet, so theres little I can do to check the delta of a bios in windows at the moment, other then actually examining various bioses.

That's why I don't buy those pre-overclocked card. ;)
They aren't worth the extra money when you can actually overclock to that level :D

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Originally Posted by Richteralan

That's why I don't buy those pre-overclocked card. ;)
They aren't worth the extra money when you can actually overclock to that level :D

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that remains to be seen actually.

if one could just flash thier card, with two different bioses... then bench them, with the same PC, and same settings and all.
a few times... then average them out.

1 bios at 650/50
2 bios at 690/15

then post up the results...
then it would become alot clearer, as to whats really going on here.

yeah i had posted b4
http://www.xtremesystems.org/forums/...&postcount=105

many companies use 690+15 = 705
and origianl nvidia is 650+50 = 700.....

for that 5 MHz you paid extra like 100USD for it just gay!!

this is all crap , like i said before so why CO version cards oercloked to 565/1800 are getting 10K in 3dmark 2005 and others non CO versions cloked to 550/1800 dont ???

and why i can get 1800MHZ so easy in memory and some normal versions cant???


link in 1st post if this was real so a non CO version at 550/1800 it was the same as a CO version at 565/1800 , so why the non CO version cloked at 550/1800 only get +- 9800marks and CO versions cloked to 565/1800 get +- 10020 marks???


my card its 520 default ----geometric delta = 0

:nono: :nono: :nono:

CO versions rulez and XFX too ;)

in fact, remove delta 50 to 0 and change core from 650 to 700 i gain more point from 05, 06. i wonder delta is like veriable number, like auto adjust overclock or something....

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Originally Posted by mascaras

this is all crap , like i said before so why CO version cards are getting 10K in 3dmark 2005 and others dont ???

and why i can get 1800MHZ so easy in memory and normal versions cant???


link in 1st post if this was real so a non CO version at 550/1800 it was the same as a CO version at 565/1800 , so why the non CO version cloked at 550/1800 only get +- 9800marks and CO versions cloked to 565/1800 get +- 10020 marks???


my card its 520 default ----geometric delta = 0

:nono: :nono: :nono:

CO versions rulez and XFX too ;)

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there are some good clockers out there and some bad ones doesnt have anything to do with delta clock..... :slap:

i bealive the cloks are real , like if you set to 565/1800 its realy 565 and not 550 ;)


whatever , my delta its 0 so i think its OK

anyways.. to9 i am going to run one with delta and one without detla and see how it perform

becnhamrks benchmarks benchamrk , deltas , deltas , hoooah :toast: :toast:

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Originally Posted by lawrywild

that's not actually what the delta clock is.

basically 7 series cards have 4 different clocks, geometric core clock, shader core clock, ROP core clock and memory clock.

the shader and ROP run in 3d at whatever you clock them to in coolbits etc. (though they only have speedbumps every 27mhz.)

the geometric core clock is the one thats affected by the delta, it's basically the above clocks + the delta value. the geometric core clock doesnt clock in 27 mhz steps though, which is why you will see a minor increase in speeds even without going up in 27mhz steps. :)

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Exactly :toast: For those who think its 3D Mode - its not ;)
7900GTX PNY 650/1600 stock clocks with +50MHz Geom. Delta :

http://img507.imageshack.us/img507/6166/rt5jz.gif

Deltas help....but it makes sense to run your GPU at the max clocks of each clock....sometimes the geom clock is the limiting clock.

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Originally Posted by GoriLLakoS

@eva2000 ...can you give the link of the full thread over guru3d???:D

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click link http://forums.guru3d.com/showpost.ph...postcount=1172 then in top right corner thread: has a link to full thread ;)

http://forums.guru3d.com/showthread....65#post1664365

Hmm, interesting too see this but I am not surprised the way they
went back with gdc's on the 7900's. They took the gdc's right out on the
7800 512mb core and now were back with them.
Haven't played much with my 7900gtx since I got it,
but this is good info to start on some 7900 bios edits/revisions, Thanks!.

Running 60 gdc's oppose to 50 in performance 3d lvl
helps about 100 points or so in 3D 05.

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Originally Posted by Vapor

Deltas help....but it makes sense to run your GPU at the max clocks of each clock....sometimes the geom clock is the limiting clock.

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but if we lower the delta to regain some clock speed how much performance is to be gained?... i guess that depends on the card but i dont think the difference would be that big if anythin... if i could only find some benchmarks with different delta clocks on a 7800/7900... my 7800gtx has a delta of 50 by default and i seem to be getting decent clocks out of it without volt mods.... im hitting 510/1380 benchable... so anyone out there running lower delta at 520mhz or more on a stock 7800gtx?