AMD RX 6900xt / 6800xt / 6800 Overclocking tweaks , tricks and mods.

[chispy]

And ...  we got a couple of new World Records today with Powercolor Red Devil Ultimate 6900xtx-h clock speed at 3306Mhz ~ 3274Mhz ( highest core clock in the world for a gpu benchmark stable ) and highest ever 3dmark Firestrike Extreme score. It was done by none the less the good guys OGS from Greece , congratulations on such a huge achievement.  Absouletely Massive score ?

https://hwbot.org/submission/4745694_ogs_3dmark___fire_strike_extreme_radeon_rx_6900_xt_35869_marks

 

 

 

Edited May 12, 2021 by chispy

[chispy]

new WR at 3321Mhz core clock , almost 38k ?, keep them coming @FireKillerGR , @phil @OGS well done ...

 

 

 

 

[chispy]

@buildzoid posted an awesome guide and help on how to make custom power tables for rx 6900xt on his latest youtube video. Go watch it as it is very helpful and informative and is a new way of helping this rx 6xxx gpus really fly. Thank you @buildzoid .

 

 

Edited May 12, 2021 by chispy

[buildzoid]

17 hours ago, 4n0nym0u5b3nch3r said:

Would ReBAR make a difference in FS/E/U?

 

I tried it. It helps a little but seems to make core stability slightly worse.

[Waffl3Ninja]

hey folks, sorry its been a few days. so this is what i know so far after talking to a few people amongst the forums.  the xfx merc 319 black edition is an actual reference card design which now actually makes sense as to why it has the 2x8pinout instead of the factory oc'd 3x8pinouts. 

just doing a little more research on my end before i start doing full on testing to the limits. i do however have a question.  

does anyone know of any aftermarket psu 8pin out cables that exceed the recommended 150watt per cable. I understand that good psus can easily push 300w per cable, but the cable itself isnt rated for 150watts.  i dunno if that makes sense haha.  i mean i have a good psu i have 1300watt titanium 80 from seasonic. but im more worried about the cable itself. any suggestions?

 

so far with basic testing and benching,  using the mpt tool just using the soft power play tables.  I am able to easily run 360w @ 375amps (following the calculations for watt and amperage found on igorslab one of the forum posts) which then allows me to raise the minimum cclock and near the limit of the card. which is 2660. i can push it to 2580 before the temp trips wattman to restart. if i dont move the minimum the card crashes at 2450.  

and ps. i will gladly accept any ideas or variations for testing so it can be as complete as possible. thanks guys

(dont roast me for the no pics its just the beginnning. ill be posting full documentation with pics. )

ok new info with this edit. about 20 minutes after iposted this one. found the derbauer 8pin out discussion.  just wanted to edit this for transparency with you guys following it. 

Edited May 15, 2021 by Waffl3Ninja
new information

[Waffl3Ninja]

12 hours ago, Waffl3Ninja said:

hey folks, sorry its been a few days. so this is what i know so far after talking to a few people amongst the forums.  the xfx merc 319 black edition is an actual reference card design which now actually makes sense as to why it has the 2x8pinout instead of the factory oc'd 3x8pinouts. 

just doing a little more research on my end before i start doing full on testing to the limits. i do however have a question.  

does anyone know of any aftermarket psu 8pin out cables that exceed the recommended 150watt per cable. I understand that good psus can easily push 300w per cable, but the cable itself isnt rated for 150watts.  i dunno if that makes sense haha.  i mean i have a good psu i have 1300watt titanium 80 from seasonic. but im more worried about the cable itself. any suggestions?

 

so far with basic testing and benching,  using the mpt tool just using the soft power play tables.  I am able to easily run 360w @ 375amps (following the calculations for watt and amperage found on igorslab one of the forum posts) which then allows me to raise the minimum cclock and near the limit of the card. which is 2660. i can push it to 2580 before the temp trips wattman to restart. if i dont move the minimum the card crashes at 2450.  

and ps. i will gladly accept any ideas or variations for testing so it can be as complete as possible. thanks guys

(dont roast me for the no pics its just the beginnning. ill be posting full documentation with pics. )

ok new info with this edit. about 20 minutes after iposted this one. found the derbauer 8pin out discussion.  just wanted to edit this for transparency with you guys following it. 

ok so update. so after watching and reading the debauer 2x8pin out vs 3x8pin out based on what he and others have said. is that if the 8pins actually follow ATX specs there is really no difference in power or limits for  2vs 3.  

also was able to actually reach customer care at kingpin and was able to get 8pin to 8 pin upgraded cables. will test them with ohm meter when they arrive to see if there is actual difference or i got ripped off hehe. Debauer did say tho that those cables from the manufacturer of the psu are ok tho.  mainly each wire pcie 6+2 can hold 150-170 easily. since  theres 75 coming from the pcie to begin with (i totally forgot about that when i was adding lol) so unless im putting like 500watts to the card which isnt hard tho.  3d mark i drew 480 plus before i BSODd. a few weeks ago. 

anyways thats the update on the 2 vs 3 pinout.  which is good to know so i wont be scared to push this card.  probably on monday i ll start logging the benching. and prelim tests.  

 

have a good weekend everyone. added a picture of how my rig is setup right now. nothin fancy. 

Edited May 15, 2021 by Waffl3Ninja

[chispy]

I think it all comes down to lucky draw silicon lottery at this point with the new xtx-h variant rx6900xt.

[buildzoid]

All the voltage rails I can find on my card.

IDK why there's 2 1.8V rails. The BIOS chips probably run on 1.8V and the GDDR6 obviously has a 1.8V VPP but that could be done with 1 reg not 2.

the 0.75V and 1.8V rails use MP8633 regulators. https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MPQ8633A/document_id/1052/

[buildzoid]

I added 4x4.7 uF 0402 MLCCs per VRAM chip and 3x470 uF to the Vmem VRM. Card now seems to scale all the way to 2200 mem. Starts to lose performance at 2220. Anyone else want to test?

[chispy]

1 hour ago, buildzoid said:

I added 4x4.7 uF 0402 MLCCs per VRAM chip and 3x470 uF to the Vmem VRM. Card now seems to scale all the way to 2200 mem. Starts to lose performance at 2220. Anyone else want to test?

Awesome find @buildzoid  . What voltage for v.mem ?  My memory scores best ~ 2110Mhz - 2120Mhz anything more and i loose points , it seems mine does not like to go that high.

 I'm not ready to do those mods you did yet ? , but look promising , thanks for sharing.

[buildzoid]

3 hours ago, chispy said:

Awesome find @buildzoid  . What voltage for v.mem ?  My memory scores best ~ 2110Mhz - 2120Mhz anything more and i loose points , it seems mine does not like to go that high.

 I'm not ready to do those mods you did yet ? , but look promising , thanks for sharing.

Stock (1.35V) Vmem. The stock cap configuration is kinda shit. Just compare the back of a 2080 Super to a 6900XT

[chispy]

RX 6900XT Red Devil Ultimate teardown by @buildzoid . Very interesting video , watch it here on his youtube chanel:

 

 

 

[GtiJason]

 

[buildzoid]

Found the I2C header pads. No need to solder wires really close to the VRM controllers.

PCB picture from: https://www.techpowerup.com/review/powercolor-radeon-rx-6800-xt-red-devil/3.html

 

In other news the mem cap mod is not as effective as it intially seemed. It's not +50MHz more like +20MHz.

Edited May 26, 2021 by buildzoid

[chispy]

9 hours ago, buildzoid said:

Found the I2C header pads. No need to solder wires really close to the VRM controllers.

PCB picture from: https://www.techpowerup.com/review/powercolor-radeon-rx-6800-xt-red-devil/3.html

 

In other news the mem cap mod is not as effective as it intially seemed. It's not +50MHz more like +20MHz.

Nicely done , i'm glad you found other pads for the i2c header pads. This is the loacation i found and use on mine ( see picture attached ) . Also you seem to have a very good memory controller on yours as most 6900xt  cards tops at 2120~2150Mhz out of the box , so 2190Mhz on yours is very good and the only card i have seen been stable at those mem clocks.

 

 If you can get the card cold on water chiller or good water cooling ambient you would be running 2900Mhz + on that card. Since there are no blocks yet available for this Red devils i will show you the easiest way to get a water block on it ( not the prettiest looking set up but it works for my card on water chiller ). Get one of those cheap chinnesse water blocks , attach a metal bar on top of it with hot glue or crazy glue , make sure you drill holes on the metal bar exactly where this 2 spots are ( shown in the picture ) and you are good to go. Place a couple of finger shredding delta or noctua 3000+ rpm high cfm fans over the vrm and memory and voila you are good to go. This ghetto mod for chilled water cooling has not failed me ?

 

 

Edited May 26, 2021 by chispy

[chispy]

Will test my RDU 6900xtx on ln2 next week and i hope it does not have a very low cold bug and cold boot bug -45c~ -50c like my last 6900xt was a pita to even run on SS ?  , cross fingers for this new one ?

[wimpievanzyl]

@buildzoid Hi can you perhaps share the pin layout of the soldering pads you discovered to connect the EVC tool. I am a bit new with the tool so I am not sure what will happen if I screw up and reverse the signal wires going to the controller or screw up and solder the GND to the wrong connection on the I2C pads.

[buildzoid]

pin nearest to Vcore VRM is GND

[Pablluca]

On 5/20/2021 at 7:53 AM, chispy said:

I think it all comes down to lucky draw silicon lottery at this point with the new xtx-h variant rx6900xt.

Chispy, tomorrow I'm receiving a Sapphire Nitro+ AMD Radeon RX 6900 XT Special Edition, but I have the option to change it for a PowerColor Radeon RX 6900XT Liquid Cooled 16GB. I just recently discovered about the new XTXH chips...if money its not a problem...Should I return the Sapphire and get the PowerColor Liquid Cooled? Thanks for any help you can give me in advance!

[chispy]

19 minutes ago, Pablluca said:

Chispy, tomorrow I'm receiving a Sapphire Nitro+ AMD Radeon RX 6900 XT Special Edition, but I have the option to change it for a PowerColor Radeon RX 6900XT Liquid Cooled 16GB. I just recently discovered about the new XTXH chips...if money its not a problem...Should I return the Sapphire and get the PowerColor Liquid Cooled? Thanks for any help you can give me in advance!

Definitely , make sure is the Powercolor Red Devil Ultimate xtxh chip as it is well worth it in my opinion a much higher better bin chip that scales with cooling and voltage. Go for it and enjoy it ? !

Edited July 14, 2021 by chispy

[Pablluca]

1 hour ago, chispy said:

Definitely , make sure is the Powercolor Red Devil Ultimate xtxh chip as it is well worth it in my opinion a much higher better bin chip that scales with cooling and voltage. Go for it and enjoy it ? !

Muchas gracias Chispy!! Well it seems that the Liquid Cooled PowerColor that is available its not the ultimate version...probably the first LC version so no xtxh chip....I thought that every LC version came with the xtxh chip but no...unlucky!

[chispy]

You are welcome @Pablluca . Sorry to hear that as the non xtxh chip is a huge gamble silicon lottery , i hope you get lucky and get a nice chip if you decide to buy one.

 

Kind Regards: Angelo

[Pablluca]

14 hours ago, chispy said:

You are welcome @Pablluca . Sorry to hear that as the non xtxh chip is a huge gamble silicon lottery , i hope you get lucky and get a nice chip if you decide to buy one.

 

Kind Regards: Angelo

Since the powercolor is not the ultimate version I have decided to keep my nitro+ special edition, I'm a newbie in this OC world, haven't done one in my life yet, but I will let you know guys what the results are for my 6900xt. I only did a gpu userbenchmark and got 195% not a very good result for a nitro+ SE...I will work around a bit to see if I can get closer to the 200% mark which is closer to the highest score. I should start with an UV + OC right? Any YTube channels to start learning about it? Thanks again Angelo!

[chispy]

@Pablluca , Learn the video card first with power limit and voltages maxed out in Radeon software ( of course fan at 100% ). Start with the core around 2600Mhz ( max ) 100 hundred mhz lower ( minimum in amd wattman ) for a good start point , go up by increments of 25Mhz until it becomes unstable in Timespy benchmark , then write down the maxed out OC of the core on a notepad. The same with the memory start around 2100Mhz + 25mhz up at a time until you either get black screen , crash to desktop , see anomalies like flashes of light sprites or if is stable check that your benchmark score goes up and not down as memory is tricky on this video cards as sometimes what it seems 100% stable will give you lower scores in benchmarks. Example my ASRock OC Formula rx 6900xtxh can run flawlessly up to 2200Mhz memory but it score lower in benchmarks , sweet spot is 2160~2170Mhz. Same applies to all rx 6900xt.

Once you have found your max core and mem overclock run timespy with core and memory maxed out if is stable and it gives you a good score then start to play and learn how to use MorePowerTool by Igor's lab ( https://www.igorslab.de/en/morepowertool-amd-radeon-rx-5700-and-rx-5700-xt-tweaking-and-overclocking-software/  ) and watch @buildzoid youtube guides how to make soft power tables - 

 

Good luck and overall have fun with it.

Kind Regards: Angelo

Edited July 16, 2021 by chispy

[chispy]

3 hours ago, Joaquin10 said:

What happens with  ATI / AMD SET LOD 10 ...

 Set LOD still works as before only in some DX9 benchmarks. I wish someone would make it work in DX10 , 11 and 12.