Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

How to make Link speed 2.5GT/s to 5.0GT/s on ATI card and Nvidia card

MacVidCards said:
let it go please
Click to expand...

No, its fun and you are the one creating drama. You left for a reason some time ago.

Also, on the GPU GT/s side of things. An increase from 2.5 to 5 GT/s will have an effect assuming the 2.5GT/s are being used and more bandwidth is required by the application. Otherwise, its like adding 2 more lanes of road to an already empty 6 lane highway.

More to the point, you must weigh in the entire draw back of incorrectly soldering one of those micro resistors.
 
MacVidCards said:
let it go please
Click to expand...

The cat is out of the bag mate, unfortunately for you, fouel releasing this information is kinda beneficial for people like me, even if the source of the information is contested.

Perhaps you should make a big point of releasing such information to the community which gets your name out there more and hence more sales?
Reputation is everything...


Tesselator said:
So, you guys who made this mod: Any noticeable speed increase? If so what was increased, what apps etc.?

Thanks.
Click to expand...

I'm not expecting much, if any, improvement.

I just feel a bit adventurous and I won't have the time or the resistors to do it until next week!!

Besides, I need to practice soldering before I do it to my 7xxx series card which certainly sees a difference in some games!!
 
Here is a pic of the 7950 from Gigabyte. NS906/NS907 is the only 3 way resistor pad that is marked. Perhaps this is the magic location on the 7950.

:cool:
 

Attachments

  • 7950 pcb.png
    7950 pcb.png
    941.3 KB · Views: 933
Here is a shot of the back of the Sapphire 7950 Mac Edition. Checking against boards with the same layout from MSI and XFX, (thx newegg) their layouts, as well as Gigabyte's, has two horizontal resistors in place.

On the 7950 Mac Edition
(Left Resistor) appears to be missing
(Right Resistor) appears to be in a vertical Orientation.

Can someone confirm what resistors are in place on the back of the 7950 Mac edition?
 

Attachments

  • sapphire 7950.png
    sapphire 7950.png
    287 KB · Views: 1,236
Last edited:
handheldgames said:
Here is a pic of the 7950 from Gigabyte. NS906/NS907 is the only 3 way resistor pad that is marked. Perhaps this is the magic location on the 7950.

:cool:
Click to expand...

You are probably right, it's always the same resistor.
You just have to follow the second pin from the right side of the crossfire connector and move the first resistor connected to it.
Anyways, the mod worked also for my non-reference-layout HD4870. The resistor was somewhere else and had another name, bud did the same job.

----------

Nevertheless, I have no idea how a pull-up resisitor near the crossfire connector can influence the PCIE link speed...
Do you know whether it's really changing to 5GT/s or if it's just changing a bit for the reported speed?
Anyways, i'ts an interesting mod.
 
Is it possible there is no resistor on the left of the sapphire card because there is no crossfire on OS system?

It will be great to have confirmation of the resistors in place...
 
Such logic inputs usually default to a certain value set by on-chip pull resistors if no external resistor is present.
I would therefore take a 10k 0402 resistor and test both positions... this is very unlikely to damage the card in any way.

I would try it myself, but I lack one of the ingredients: the card. :(
 
Muahahaha!!! Great news!!! Here is what we know:

There are two different PCB layouts:

PCB Layout A) 7950 - 7950 Mac Edition & Others - chips below crossfire connectors with horizontal / vertical orientation. No resistors .

PCB Layout B) 7950 - Most cards on Newegg - chips below crossfire connectors with 45 degree angle layout. Two resistors


1) SAPPHIRE FleX 100352FLEX-2 Radeon HD 7950 - Layout A - 2 resistors at this location. Hmmmm

2) HIS H795QMC3G2M Radeon HD 7950 3GB - Layout A - No resistors at this location

3) SAPPHIRE 100352-2L Radeon HD 7950 3GB - Layout B - 2 Resistors in place.

4) GIGABYTE GV-R795WF3-3GD Radeon HD 7950 3GB - Layout B - 2 Resistors in place.

5) Cards with the resistors in place list their specs showing: Effective Memory Clock: 1250MHz (5.0Gbps)

If anyone is flashing their card with the modded EFI Bios, would be good to hear what card you have and if you are running at 5.0GT/S
 
I have a powercolor 7950 PCS+ (Layout B =2 resistors).
My rom is flashed (I have the boot sreen). I removed the two resistors but the card still running at 2,5GT/s. I tried also with the two resistors at vertical position but It runs also at 2,5GT/s.

So It seem's we must find another solution....
 
J-MI said:
I have a powercolor 7950 PCS+ (Layout B =2 resistors).
My rom is flashed (I have the boot sreen). I removed the two resistors but the card still running at 2,5GT/s. I tried also with the two resistors at vertical position but It runs also at 2,5GT/s.

So It seem's we must find another solution....
Click to expand...

Excellent progress. Modifying two of the positions at a time may be hiding the result we are looking for. Luckily, there are more combinations to try. One of these hopefully should deliver what we are looking for. Hey MacVideoCards - any thoughts?

Left = towards power connectors
Right = towards video connectors

Left - vertical | right - none
Left - vertical | right - horizontal
Left - vertical | right vertical No effect

Left - Horizontal | right - none
Left - Horizontal | right - horizontal
Left - Horizontal | right vertical

Left - NONE | right - none - No effect
Left - NONE | right - horizontal
Left - NONE | right vertical
 
Last edited:
handheldgames said:
Excellent progress. Modifying two of the positions at a time may be hiding the result we are looking for. Luckily, there are more combinations to try. One of these hopefully should deliver what we are looking for. Hey MacVideoCards - any thoughts?
Click to expand...

Why ask me? Fouley-Poo has all the answers. He started the thread, after all. Isn't he the one with a 7970 on Ebay running at 5.0? Ask him.
 
Last edited:
MacVidCards said:
Waiting for the wisdom from Foul, he knows best.
Click to expand...

Well we can't be that far off. It has to be one of the two points I identified - just need to find the right combination. Would be a great share to the community here at MR. After all, most Mac users are afraid of using a 3rd party card, let alone to modify one.

Unfortunately I don't have experience soldering at that size nor the right equipment else this would be a non-issue.

fouel said:
It seems no resistors near crossfire connector.
Click to expand...
Any thoughts foul?
 
I've got the soldering station, the skill (soldered Nintendo screens for a living back in the day) and the 10 kΩ chip resistors.... but no board!
If they drop in price below $300 here in Tokyo, I can give it a try :).

handheldgames said:
Agreed. I must be on to something if neither are willing to respond. Guess it's time to invest in a better soldering setup so I can take credit and share it with the world.. :rolleyes: :rolleyes: :rolleyes:
Click to expand...
 
nekton1 said:
I've got the soldering station, the skill (soldered Nintendo screens for a living back in the day) and the 10 kΩ chip resistors.... but no board!
If they drop in price below $300 here in Tokyo, I can give it a try :).
Click to expand...

Good luck.

Just know that when you have put the hours in testing various combos, potentially killed a card or two, burnt your fingers and finally get the answer, Fouley-Poo will be on here bragging that HE figured it out.

Just noticed that EBay is already FLOODED with flashed 7950s and 7970s, most mired down in PCIE 1.0 speeds. This means they will still be plugging along at low speeds when Mac Pro 6,1 comes out at 3.0.

Oddly, even Foul is selling ones stuck in 1st gear. Hmmmmm.....
 
Last edited:
The 7950? They're ¥22,000 here in Nagoya. I don't remember what maker but it was a golden-brown/yellowish box.

nekton1 said:
I've got the soldering station, the skill (soldered Nintendo screens for a living back in the day) and the 10 kΩ chip resistors.... but no board!
If they drop in price below $300 here in Tokyo, I can give it a try :).
Click to expand...

LOL I was trying to find which one it was when I saw THIS and laughed my butt off. Hehehhe $1,200 for the mac version. Bahaaahahahaaa
​

I think it was this one Tho I guess it could have been this. There was a stack 2x2 and waste high with a sign atop saying ¥21,980. At least the box color is about right for those two. It was at Goodwill Nagoya. But I don't see it on their webpage at all:
http://www.goodwill.jp/goods/search.php?pc=50&pp=1&c=7&c1=0405&c2=040501&sort=pr
 
Last edited:
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back