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


h9826790

macrumors G5
Apr 3, 2014
12,801
5,622
Hong Kong
I did R17 mod on my HIS R9 280 some time ago. And after that, I confirmed there is virtually no gain on such low level card (using 2017 standard). And I suspect that's the reason why no one interesting in the 5870 mod. This card is very old now, not many members here still running this card (especially the active members). Also, most of us know the gain in real world is virtually zero in most of the time.

However, even though I have no intention to mod my current R9 380 but I still interested in how you find the relative resistor on other cards. 5870 is understandable, because there is a Mac version to follow / compare.

However, the R9 270X has no reference. Or it's also named R17 because it's also a GCN 1st gen card?

I personally believe even though RX580 doesn't quite need this mod. I assume it can gain few % for most operation, but that's it. Still not quite worth to take the risk. But I am sure quite a few guys interested in it, especially if there is a way to make the Sapphire PUSLE RX580 8GB run at PCIe 2.0.

Also, the coming Vega is another story, I assume PCIe 1.1 x16 can be the bottleneck for this card (when the software / driver mature).

I wonder if you have a systematic way to find out the key resistor. And if this kind of method will work on the Polarise / Vega graphic cards.

Anyway, if you prefer to keep it as a secret, that's fine. I 100% respect your decision. You have no responsibility to share your finding to us. But I just want to let you know my point of view why seems no one interested in the 5GT/s mod on that particular card. It's not no one appreciate your work / sharing, but simply that's an outdated card for most active members. We may not even have the card on hand to test your finding. Hard to give any feedback to you.

However, if you willing to share your methodology on how to find the key resistor. I am quite sure few guys here will be more interested to join the discussion, and may even try to make it happen on the new GPUs.

In fact, I don't mind to take the risk on my R9 380 to test your theory, but it's all up to you if you willing to tell us about your finding, and if I can follow the logic, and reasonably believe why that one should be the key resistor.
 

LightBulbFun

macrumors 68020
Nov 17, 2013
2,128
1,945
London UK
@MIKX
ill also say, im sure theres many out there (me included) that are very much interested in reading your guides and findings, this information is very valuable to others in this community, without guides like yours and others in the past, id probably not be where I am today

if you can please dont delete your guides, they are very handy for anyone in the future with a 5870 they wish to mod, the 5870 is still a very nice upgrade for 1,1-3,1 users who have lower end cards.

I my self have a done a few guides and posts that have received little or no comments, but I dont let it deter me from tinkering with Macs and writing up posts :)

here are a few examples

https://forums.macrumors.com/threads/mac-os-8-6-findings-and-ramblings.2021922/ this one of running Mac OS 8.6 on unsupported macs has no responses

https://forums.macrumors.com/threads/eeprom-replacement-and-flashing-x850-xt-rom-on-firegl-x3.2016538/ and this post about modding a FireGL X3 to an X850 XT (which involved not only hardware modding but also modification of the ROM firmware), also has 0 responses

just because these posts got no responses does not mean im going to just pack up shop, despite the fact these posts got no responses im sure in the future or now, someone is trying to find information that happens to be contained in those posts will be very happy when they find it in my posts :) for these and many other reasons its why i still continue to post even in the light of little or no commentary
 
  • Like
Reactions: Synchro3 and owbp

pierrox

macrumors regular
Jun 19, 2015
164
55
Paris, France
Yep, agreed with my colleagues 100% You shouldn't get on your high horses because no one threw a "that's genius" comment. The hype is all about the new AMD cards and how they suck vs Nvidia. But if you can put a "Apple logo boot screen" rom on a RX580, you'll get your 15 minutes of fame for sure!
 
  • Like
Reactions: LightBulbFun

thomasthegps

macrumors regular
Sep 23, 2015
218
143
France
Honestly, people on forums compared the PC Cards and their Mac counterparts and noticed that some resistors on PC or Mac cards where either missing or moved. Thats pretty much all you need to know. This guy is trying to make it sound like he's above everyone else, I say good riddance. Him saying he is keeping that knowledge a secret for whatever reason makes me doubt his "achievements". If you do not wish to become an "Internet Mac expert" create a post detailing how to find the resistors and people will respect you and go on from there. But don't feed the community that pre-teen BS about how you are unloved.

When it comes to the RX 580 since there is no Mac counterpart available for the Mac pro, the chance of getting 5GT/sec is slim if we don't help each other.

How does the GPU or any PCIE card know at what PCIE speed to run while the PC or Mac is booting ?
How do we know that the RX 580 still uses the same method to set it's PCIE speed compared to the older cards ?
 
Last edited:

MIKX

macrumors 65816
Dec 16, 2004
1,215
454
Japan
I will leave the 5870 & 7950 guides up. I only put them up because invarialby existing guides photos are too small to gain any useful info. Rominator & Nekton1 confirmed that the mod works. I merely re-confirmed this.

As for the R9 270 X. 2Gb should the 5.0 GT/s mod be revealed you can be sure that they will suddenly start appearing on eBay . . .. . as flashed /5.0 GT/s cards I don't intend to make it easier for these resellers - let them learn how to as I had to.

I used a Kamikaze method in locating the R9 270X resistor using a jeweller's headset, a very fine soldering iron. copper solder sucking gauze. a mini-vice to securely hold the card, extremely fine tweezers, a range of HB pencils ( 2HB ~ 4HB ) and a very soft eraser.
I found the resistor. . you can find it too. That is the point.

========================================

HINT : In the case of the HD 7950 the resistors are either in a regular checker board or staggered arrangement South West of the bottom left cooler retaining screw.

Another favoured position ( for other cards ) is just South ( or Sth. West ), depending on the PCB version - of the CrossFire connector in either a vertical two resistor arrangement or a vertical three resistor arrangement with two of the three connected with a resistor. This is where experience. intuition & familirarity with the relevant and other branded reference cards comes into play.

=========================================

My original intention was to help cMP people learn how to think the mod through.

I got pi**ed off waiting for anyone to re-confirm that this mod works on cards OTHER THAN the HIS 5870 & Sapphire Varpor-x 1 Gb cards.

If the above resistor positions and arrangements appear in newer cards . . . . . .

I re-iterate that Apple apparently deemed having a 5.0 GT/s link speed essential on their cards.
Perhaps it reveals it's purpose under high load apps/games.

Thanks for the personal attacks.

PS : I'm 67 years old -Started out on Amiga 2000's and the A4000T. Modded them too.
 
Last edited:

Fl0r!an

macrumors 6502a
Aug 14, 2007
906
525
Great work finding the resistor on R9 270X! I guess it might make more sense to use a HD 7870 though, since those cards have a matching framebuffer personality (Futomaki). The 270X will lose some ports in macOS due to mismatched connectors. That shouldn't happen on reference 7870's.

Resistor location might be the same, as those cards are closely related...?
 

MIKX

macrumors 65816
Dec 16, 2004
1,215
454
Japan
I already have 7 cards .. no 7870. 7970 next or higher. I'm still paying for my two kids university fees so might be a while.

Fl0r!an, why do you think Apple enabled 5.0 GT/s on so many of their retail cards? Possible it was for a future OS X CrossFire adoption ? What would 5.0 GT/s be used with ?
 

h9826790

macrumors G5
Apr 3, 2014
12,801
5,622
Hong Kong
Great work finding the resistor on R9 270X! I guess it might make more sense to use a HD 7870 though, since those cards have a matching framebuffer personality (Futomaki). The 270X will lose some ports in macOS due to mismatched connectors. That shouldn't happen on reference 7870's.

Resistor location might be the same, as those cards are closely related...?
That's what I am thinking. 270X and 7950 both belongs to GCN 1. Their PCB may be similar. The chance that the same R17 resistor doing the same job is not too slim. So, it's possible to locate it. However, if the key resistor is not R17. Then I am really surprised that MIKX can find it. That's definitely not an easy job, require lots of testing, studying, thinking, and finally brave enough to physically remove it to confirm if that's really the correct resistor.

I can imagine even if at the similar location, with similar resistor layout, but the key resistor has a different name. That's already really hard to identify the correct one.

I got pi**ed off waiting for anyone to re-confirm that this mod works on cards OTHER THAN the HIS 5870 & Sapphire Varpor-x 1 Gb cards.
I really believe that your expectation is too high. As I said, most active members already moved on, and do not have 5870 on hand anymore. It's impossible for us to confirm your finding if we don't have proper card to test it.

Some members may still using 5870, however, some of them are using the Apple 5870. And the rest may be very happy with the current performance (otherwise they should already upgrade the card long time ago). And I suspect most of them are relatively conservative (otherwise, they may already move on to the non-Apple officially supported GPU). Under this situation, it's hard to have anyone can confirm your finding in short period of time (even in few months).

If your finding is on any RX card. Then I am sure the situation will be very different. But since both the 5870 and 270X is a pretty old card now, and their performance simply don't need 5GT/s negotiation (under normal situation, they can even saturate a 2.5GT/s x16 connection). I doubt how many (conservative) guys who still running 5870 willing to try your mod.

And 270X is even harder to get anyone to test the mod (even you disclose everything). If anyone willing to run a 270X, most likely will choose 7950, or 7970. I rarely see anyone discuss 270X here. In this case, we really can't expect anyone interested in that particular card's mod.

Again, I totally respect your decision. And appreciate your sharing. If you willing to tell us how to actually determine the key resistor (if that's no R17) on the 270X. I am sure more guys willing to join the discussion / study. Or even willing to test on their newer card. But if you still decide to keep it, because don't want your work help those eBay guys to scam the others, that's totally understandable.

I have no intention to attack you. But just believe that your expectation is really too high. If you unhappy because of that. I will say better let go. It's not anyone's fault. And I still wish to see how you determine the key resistor on 270X if possible.
[doublepost=1503341380][/doublepost]
I already have 7 cards .. no 7870. 7970 next or higher. I'm still paying for my two kids university fees so might be a while.

Fl0r!an, why do you think Apple enabled 5.0 GT/s on so many of their retail cards? Possible it was for a future OS X CrossFire adoption ? What would 5.0 GT/s be used with ?
Crossfire itself doesn't need 5GT/s

I ran 7950 crossfire on my cMP (of course, in Windows). The card that with 5GT/s x4 connection has roughly the same performance as the card that has 5GT/s x16 connection. By considering 5GT/s x4 = 2.5GT/s x8. I really can't see why 5GT/s x16 is important on these cards. And why Crossfire will need it.

https://forums.macrumors.com/threads/mac-pro-5-1-owner-make-it-your-king-of-mac-with-2-d700s.1732849/page-5#post-21722712
 

thomasthegps

macrumors regular
Sep 23, 2015
218
143
France
The only 5870 I have died years ago. I saw your post on the netkas forums but I don’t see what i could have added to the discussion, this is probably true for many others.

Also, I don’t understand the logic. If the knowledge about finding these resitors is shared, I would expect most people to mod their cards themselves and not buy something off ebay that costs an arm and a leg. At least i wouldn’t. Also How do we know that AMD doesnt use a softrap like nvidia for their modern cards? Maybe newer cards dont have this “magic” resistor. What makes you so sure that these resitors still exist on newer hardware? What is a kamikaze method?
 
Last edited:

thomasthegps

macrumors regular
Sep 23, 2015
218
143
France
Ok thats what I thought. Has anyone tried the Mac Pro PCI offset command to get 5GT/sec on the netkas forums ? If so has it worked ?
 

h9826790

macrumors G5
Apr 3, 2014
12,801
5,622
Hong Kong
Ok thats what I thought. Has anyone tried the Mac Pro PCI offset command to get 5GT/sec on the netkas forums ? If so has it worked ?
Do you mind to post the link here? I don't mind to study that and have a try (if I can understand how to do it properly).

Update 1: I found it

http://forum.netkas.org/index.php/topic,13541.0.html
[doublepost=1503350410][/doublepost]Read that, sounds very straight forward. However, I am encoding video at this moment. Still need at least another 30 hours to complete. And tomorrow, I will be out of town for few days. I may try that on next week.

But it seems there is a problem.

From memory, boot screen is required, otherwise can't see anything in rEFIt.

And this method seems need to repeat on every boot. Otherwise the PCIe speed will automatically fall back to PCIe 1.1.

That means, only flashed card can use this method (Apple card already run at PCIe 2.0, so only flashed card need it).

The script can make everything work automatically, including boot to default OS after PCIe 2.0 set. That means, it's possible to use an EFI card (e.g. GT120) to finish all the setup and then swap a non EFI card (e.g. RX580) back in. However, this will make the system only can boot to the default OS.

I didn't use rEFIt for quite a few years, can't quite remember how it works. But from memory, it override the normal boot manager, and the OS selection in system preference. That means, without boot screen, this PCIe 2.0 software mod can only apply on a single OS system, and the cMP will always boot to that system.

If this restriction exist, then
Apple GPU don't need it.
Unflashed Nvidia GPU don't need it (in MacOS)
Nvidia flashed card don't need it (already has PCIe 2.0 in any OS)
AMD flashed card generally don't need it (we can simply remove the R17 on the most popular card)
Both AMD (any OS) and Nvidia unflashed card (Windows) can't use it (without co-install another EFI card), otherwise, the cMP can only boot to the default OS.

So, the only useful case almost down to a cMP that has both an AMD non-flashable card, and an EFI GPU installed.

Do I miss anything? Or rEFIt can work without bootscreen now? Or rEFIt won't override the boot drive selection in system preference?
 

thomasthegps

macrumors regular
Sep 23, 2015
218
143
France
well refit only works with a boot screen, but you can put two GPUS in the Mac Pro one that has EFI and one that doesn't use the EFI GPU to boot rEFIT and make the changes necessary. For example use a GT120 Mac edition and a RX 580.
 

keiffro

macrumors newbie
Dec 1, 2017
1
0
In response to post #72. Thank You, Thank You, Thank You! This works perfect on a Club HD 7950 '13s Unloaded (Type 1 or A design). As a side note for the Noobs out there. Instead of using a soldering iron to remove R17, I simply took some high quality side cutters (the sharper the better) and crushed/cut the resistor. Then just clean up the debris with a watch/glasses type screw driver. 5GT/s reported by High Sierra!
 

itdk92

macrumors 6502
Nov 14, 2016
481
174
Copenhagen, Denmark
I did R17 mod on my HIS R9 280 some time ago. And after that, I confirmed there is virtually no gain on such low level card (using 2017 standard). And I suspect that's the reason why no one interesting in the 5870 mod. This card is very old now, not many members here still running this card (especially the active members). Also, most of us know the gain in real world is virtually zero in most of the time.

However, even though I have no intention to mod my current R9 380 but I still interested in how you find the relative resistor on other cards. 5870 is understandable, because there is a Mac version to follow / compare.

However, the R9 270X has no reference. Or it's also named R17 because it's also a GCN 1st gen card?

I personally believe even though RX580 doesn't quite need this mod. I assume it can gain few % for most operation, but that's it. Still not quite worth to take the risk. But I am sure quite a few guys interested in it, especially if there is a way to make the Sapphire PUSLE RX580 8GB run at PCIe 2.0.

Also, the coming Vega is another story, I assume PCIe 1.1 x16 can be the bottleneck for this card (when the software / driver mature).

I wonder if you have a systematic way to find out the key resistor. And if this kind of method will work on the Polarise / Vega graphic cards.

Anyway, if you prefer to keep it as a secret, that's fine. I 100% respect your decision. You have no responsibility to share your finding to us. But I just want to let you know my point of view why seems no one interested in the 5GT/s mod on that particular card. It's not no one appreciate your work / sharing, but simply that's an outdated card for most active members. We may not even have the card on hand to test your finding. Hard to give any feedback to you.

However, if you willing to share your methodology on how to find the key resistor. I am quite sure few guys here will be more interested to join the discussion, and may even try to make it happen on the new GPUs.

In fact, I don't mind to take the risk on my R9 380 to test your theory, but it's all up to you if you willing to tell us about your finding, and if I can follow the logic, and reasonably believe why that one should be the key resistor.
VEGA works at x16, 5GT/s on Mac Pro 5.1
 

h9826790

macrumors G5
Apr 3, 2014
12,801
5,622
Hong Kong
Why should it not be accurate?
It says my card running at 2.5GT/s, but test result shows 5GT/s
Screen Shot 2018-03-16 at 06.17.07.jpg
5GT:s.jpg

On the other hand, it says the Vega can run at 8GT/s. Apart from it's totally impossible for a cMP, the test result suggests that it's just running at 2.5GT's from the other's post.
OceanWave 1.jpeg
 

h9826790

macrumors G5
Apr 3, 2014
12,801
5,622
Hong Kong
But that’s a known nvidia bug.

Anyways, how can it be tested?
That's a known macOS bug, not a Nvidia bug. System reports is a part of the OS, made by Apple, not Nvidia.

I just show you the test, run OpenCL Oceanwave. If you have 5GT/s, you should see ~5GB/s.