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Pics Of the 7900 GS/GTX - Page 2

post #21 of 41
12/16/06 at 1:21pm
Well, thats fine. I am just stating facts that people have done irreversible damage by tampering with video card latencies... Its completely up to you whether you feel safe attempting this or not. For me, its just not worth risking 2 years of warranty. Good luck to you though, and if you have good results let us know!
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post #22 of 41
12/16/06 at 7:06pm
Ok, so what would I have to change on the 7900GTX??

I don't speakish the spanish
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post #23 of 41
12/16/06 at 10:06pm
I know what you're doing. I did the same thing with the MR9800 back in the day. You are right about the GS, It is severely "hobbled" and needs to be fully "decoded" like the old MR9800. Rep for U!

cheers,
whack
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post #24 of 41
12/16/06 at 10:19pm
Quote:
Originally Posted by sergiop
I have spoken with the guy that found this and he says that you are wrong...

He says that dell is using some latencies that do not correspond to the real latencies stated by SAMSUNG, the manufacturer of the memory. He says that he has researched several roms from diferent manufacturers and he has reached the conclusion that dells latencies are changed so no OC is allowed.

He ends by saying that this is SAFE since the memory of the gs is ment to work at 700mhz while dell has it underclocked at 500 due to the "bad" latencies that they use in their bios.
He is correct.
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post #25 of 41
12/17/06 at 7:56am
Thread Starter 
Quote:
Originally Posted by sublime_jl
Ok, so what would I have to change on the 7900GTX??

I don't speakish the spanish

Hey just open nibitior, find the memory latencies table shown in page 1, and switch the numbers from the picture to FF save the bios and apply the process...

If you dont know, just tell me the frecs you want and i will upload one for you.

BY THE WAY whackamac thanks for your confidence, for me it makes a lot of sense, gs latencies sux, you put the gtx bios with latencies close to the real value but not quite, and as a result you can increas your memory by 600mhz... makes sense to me...
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post #26 of 41
12/18/06 at 2:45pm
Quote:
Originally Posted by sergiop

If you dont know, just tell me the frecs you want and i will upload one for you.

.

As I am not sure if I got everything absolutely right and this is a very serious mod I would be grateful if you could offer the GFX-BIOS for download.

As a frequency I would prefer 600/800, that way I can alter it step by step. Thank you in advance.

By the way, apart from the ATI-Tool, do you or your spanish friend have any new GFX-temperature results, preferrably gamingwise?
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post #27 of 41
12/18/06 at 2:50pm
Thread Starter 
as far as i know no, i have gained one degree after increasing the memory from 750 to 825... so its good... He has sent me an email that i will translate to you later explaining the whys of this mod.

so here is your request:

http://rapidshare.com/files/8021828/rom.rar

600/800
600/825

625/800
625/825.

I wouldnt go above that.
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post #28 of 41
12/18/06 at 3:18pm
Thread Starter 
Ok basically im going to be translating from spanish, so if something does NOT make sense do not hesitate on telling me.


"This mod is made for the bios to load the optimum values given by the manufacturer.

This mod can be used on graphics card with the graphic chip G71( 1500m, 2500m, 7900gs, 7900gtx) that are manufactured by dell as all 4 have this memory:

- K4J55323QG-BL14 : 256MB and frecuency = 700Mhz.
- K4J52324QC-BL14 : 512MB and frecuenciy = 700Mhz.

Note: The 7950GTX does NOT use this memory so its not a valid mod for it.

With the so called mod the only thing you are doing is loading the frecuencies stated by the manufacturer and not DELL.
So in any graphics chip that uses samsung K4J55323QG-BL14 memory we are going to find these timings:

Timing 0: 0916271F
Timing 1: 0C01070C
Timing 2: 2028060A
Timing 3: 5816F809
Timing 4: 00000C1F
Timing 5: 027AC966
Timing 6: 00230119

From timing 0 and timing 2 you get the most important values for the memory functionality which is

tRC: 31 (its the sum of tRAS and tRP)
tRFC: 39
tRAS: 22
tRP: 9
tRCDRD: 10
tRCDWR: 6
tRRD: 8

Those are the optimum memory values stated on Samsung's memory data sheet.

So for you/me/everyone to know what the values our graphics card have we need to do this with nibitor:

Tools -> Read BIOS -> Select Device -> OK
Tools -> Read BIOS -> Select Device -> Read into NiBiTor
Timings -> OK -> Test timings -> GetTimings


The values shown are the values set in the memory. So if you havent had done the mod you can see that they are not quite optimum.

If we want to see what are the values set by dell on our graphics adaptor once having done the get timings step, stated above, copy in notepad both the timing 0 and timing 2, close the test timings window and paste timing 0 on the timing 0 box and timing2 on the timing 2 box on timingset 7.

then press detailed timings and you will see what the real values of the graphics card are being used... if you compare the ones used by the gs default bios they are far off the latencies stated by Samsung."


Thats the end.
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post #29 of 41
12/18/06 at 4:03pm
Thank you for the roms. I already did some testing but unfortunately it doesn`t seem to result in any performance gain for me:

Using the normal GTX/GSX-Bios I can push my card to about 625/810. Having installed the GFX-BIOS, the The nvidia-overclock-utility won`t let me go any higher than these frequencies. Artifacts and Futuremark-results are the same as with GTX/GSX-BIOS.
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post #30 of 41
12/18/06 at 4:32pm
Thread Starter 
i guess this is because the latencies from the Dell Gtx are close to the real samsung latencies.

He is using this latency mod to keep his 7900gs bios and push it to the "gtx-mod" values...
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post #31 of 41
12/18/06 at 5:57pm
Ok... some of what is going on here I think I can explain better for you all.

First off, I retract my prior statement about the GS and GTX bioses having the same latencies. I just went through and checked again, and come up with completely different results than I did the last time I checked (it pays to get sleep before digging into technical things... lol) Here is what I have found.

I loaded up the STOCK GS rom and pulled the latencies from it first...

Code:


7900GS

060F1B15 = tRC        21
09010509 = tRFC       27
20250407 = tRAS       15
5513F506 = tRP        6
00000C1F = tRCDRD     7
027AC966 = tRCDWR     6
00230116 = tRRD       5




Then I flashed back to my GSX rom and these are the GTX latencies...



Code:




7900GTX

0916271F = tRC         31
0C01070C = tRFC        39
2028060A = tRAS        22
5816F809 = tRP         9
00000C1F = tRCDRD      10
027AC944 = tRCDWR      4
00230119 = tRRD        8




SO... basically what this means is that the GTX already runs at the more relaxed latencies (exactly the ones that sergiop posted) while the GS runs at the tightened (faster) latencies. This is the exact reason why the GTX BIOS lets us clock so much higher than the GS BIOS. The GS memory runs much faster at a lower clockspeed, but cannot be pushed as far when overclocking. So if you have already flashed to the GSX BIOS from the other thread, than there is no need to touch any of these settings at all, you already have the correct latencies. If, for whatever reason, you want to keep the GS BIOS (only benefit would be that Windows would correctly identify it as a GS instead of GTX, if thats beneficial to you) than this mod is for you.
					

												
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													post #32 of 41
											

										

									12/19/06 at 10:25am											

				


				

			

				

			


	

		

		

		
	




					

						
sorry


but my timings in 7900 gs is:


0916271F = tRC 31

0C01070C = tRFC 39

2028060A = tRAS 22

5816F809 = tRP 9

00000C1F = tRCDRD 10

027AC944 = tRCDWR 4

00230119 = tRRD 8
					

												
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													post #33 of 41
											

										

									12/19/06 at 9:56pm											

				


				

			

				

			


	

		

		

		
	




					

						
I am the person who has discovered this mod in Spain.
If you use the gtx bios in your gs card (gsx), you obtain the same result that if you do not do it. It is long to explain it.<O</O

<O</O
This mod is useful is two occasions:<O</O
- 7900gs/1500m with original bios. (You obtain a great improvement like gsx).<O</O
- 7900gtx with original bios or 2500m with original or gtx bios. (You obtain a small improvement).<O</O

<O</O
Thanks and sorry for my english.<O</O
					

												
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													post #34 of 41
											

										

									12/20/06 at 1:51am											

				


				

			

				

			


	

		

		

		
	




					

						
Because I know if I attempt to do everything myself odds are I will screw something up, I was wondering if it would be possible for someone to post an Iso with the necessary files to flash the GS to higher clocks with the altered GS timings. I've overclocked my GPU using Stormlifter's old GS ISO and now the GSX iso, and I'd like to get the performance of the GSX but with the actual GS BIOS. Sorry If this is noobish, but I honestly don't know how to make my own ISO/bootable disk.
					

												
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													post #35 of 41
											

										

									12/20/06 at 4:52pm											

				


				

			

				

			


	

		

		

		
	




					

						
If this BIOS is a modded GS-BIOS, why does the system then tell that my GPU is a 7900GTX and not a 7900GS?
					

												
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													post #36 of 41
											

										

									12/20/06 at 6:22pm											

				


				

			

				

			


	

		

		

		
	




					

						
I'm too chicken to try modding this myself.
					

												
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													post #37 of 41
											

										

									12/20/06 at 8:07pm											

				


				

			

				

			


	

		

		

		
	




					

						
I did the mod to the timings as posted and I think it helped me push my memory speed.


To anyone that has not done any modding to their video card - YOU ARE MISSING OUT!


I now have my card set to 630/830 and it never gets over 75C while gaming with the dual pipe heat sink. It seems totally stable with no artifacting, and I get consistent 9700+ point runs with 3DMARK05. Pushing the card to the limit by bumping things up got me 9939, but there is was artifacting.


For all the people out there with Complete Care - whats the worry?


BigTymer
					

												
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													post #38 of 41
											

										

									12/21/06 at 10:46am											

		
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Ok, so for all.


What is good about the mem mod, basically your gs has 256mb while the gtx has 512 mb... when you do the mod your computer thinks that you have 512 when you DONT.


So what is going to happen when you need to use 300, your computer thinks that there is plenty of room but the truth is that u are lacking 44mbs... so what is going to happen? i dont know, but i dont want to find out.
					

												
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													post #39 of 41
											

										

									12/21/06 at 11:13am											

		
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i Have good news


Thanks to the pics juanlu has also found a way to alter the frecs by software WITH ATI TOOLS...


here is the proof of concept


[youtube]http://www.youtube.com/watch?v=pWDQwxRWEBY[/youtube]
					

												
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													post #40 of 41
											

										

									12/21/06 at 6:09pm											

				


				

			

				

			


	

		

		

		
	




					

						


Quote:




Originally Posted by sergiop


Ok, so for all.


What is good about the mem mod, basically your gs has 256mb while the gtx has 512 mb... when you do the mod your computer thinks that you have 512 when you DONT.


So what is going to happen when you need to use 300, your computer thinks that there is plenty of room but the truth is that u are lacking 44mbs... so what is going to happen? i dont know, but i dont want to find out.






Umm, what report under Windows shows that you have 512MB? All of my system tools, including DXDIAG (the important one) and even the Adapter tab under the display properties window correctly report the proper 256MB of RAM...
					

												
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