Glad to hear you’re working on a new kernel tuned for Polaris, as you’re still better than me when it comes to writing optimized kernels. Tonga seems to have a limit of 92-93% of the peak memory bandwidth for eth mining, so for a R9 380 clocked at 840/1500, that’s just over 22Mh. For people that haven’t read all my old posts, it’s physically impossible to get more than 24Mh (192GB/s memory bandwidth / 8KB ethash reads).
For a Rx 480 clocked at 2Ghz, 92% efficiency would be 29.5Mh, and that should be doable with a core clock of 1100. However I don’t recall seeing anyone getting over 29Mh without going over 2Ghz for the memory clock.
Better to bring the mem clock up a lot more, after loosening the timings a bit. And you can get more than 24MH/s – just obviously not at 1500Mhz memclk.
Agreed, though I find 1625 to be about average for what I can OC the RAM on Tonga cards. The best I had was a MSI R9 380 gaming that had heat spreaders on Samsung RAM, which was stable at 1700Mhz. The worst is a MSI Armor2X with cooling for only 3 of the 8 Elpida RAM chips, and is not stable over 1550.
Advertised sites are not endorsed by the bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction.
Legendary Offline
Activity: 1512
Miner Developer
Glad to hear you’re working on a new kernel tuned for Polaris, as you’re still better than me when it comes to writing optimized kernels. Tonga seems to have a limit of 92-93% of the peak memory bandwidth for eth mining, so for a R9 380 clocked at 840/1500, that’s just over 22Mh. For people that haven’t read all my old posts, it’s physically impossible to get more than 24Mh (192GB/s memory bandwidth / 8KB ethash reads).
For a Rx 480 clocked at 2Ghz, 92% efficiency would be 29.5Mh, and that should be doable with a core clock of 1100. However I don’t recall seeing anyone getting over 29Mh without going over 2Ghz for the memory clock.
Better to bring the mem clock up a lot more, after loosening the timings a bit. And you can get more than 24MH/s – just obviously not at 1500Mhz memclk.
Agreed, though I find 1625 to be about average for what I can OC the RAM on Tonga cards. The best I had was a MSI R9 380 gaming that had heat spreaders on Samsung RAM, which was stable at 1700Mhz. The worst is a MSI Armor2X with cooling for only 3 of the 8 Elpida RAM chips, and is not stable over 1550.
got some MSI Gaming X RX 480 8GB cards today at a good price ($300 CAD, with free download code for DOOM, plus additional $20 rebate) and copied the 1750 timings and 1220MHz/2150MHz to get around 29.5MH/s
should i try the 1650 timings next, and will it limit the memory overclocking?
24″ PCI-E cables with 16AWG wires and stripped ends – great for server PSU mods, best prices also selling 6″ M-F-M PCIe splitters and PCIe-PCIe No longer a wannabe – now an ASIC owner!
Yea I got a batch of Samsung based reference saph 470s and manually added the offsets, but for some reason the gpu would not post with the offset added. Weird cause offsets on Hynix/micron cards worked fine. Never had time to investigate this.
What location were you adding the offsets at? Because I don’t think they can be added at A992 for cards that dont already have a programmed offset built in. Maybe the learned folk on this thread could shed some light on how to go about adding an offset location to a bios that doesn’t have one.
Check out Overclock.net forum.
There are some threads there that’ll get you a long way to be able to add global offset.
You basically have to find the voltage table (you can find this easily with atombiosreader) Open your rom in a hexeditor, find that table, (For a lot of Sapphire models, the VDDC offset is already there) 00 8D 00 ** 00
If you want to add it you’ll need to modify the table by adding those values in that table. You then have to update the length of the VoltageObjectInfo (VOI) table & also update the length of the i2c table in VOI table <– (something a lot of people tend to forget, i remember Wolf having issues with this as well until i told him that he had to change this value too (I2C table)).
After that you have to remove the amount of bytes you added in the legacy ROM section (or the size of the rom is incorrect).
That’s not all, after doing that you have to modify the master table as well (there’s a calculator for this, also on overclock.net).
It’s not “that” difficult but the risk of bricking your card is A LOT higher here than screwing around with timings.
Greetings!
Yea I’ve added the offset to multiple BIOSes, but for some reason this specific card with samsung memory does not like it.
Yep…nvm just checked the file and realized I forgot to update the i2c length on that one
Kinda OT since this is a RAM Timings thread, but ill ask this anyways :
For Sapphire RX 470 4GB (Ref) cards GPU Core Volt offset is at A992 correct? Now for the cards with Hynix memory, I find the default 04 which is 4 X 6.25 or +25mv, which seems legit. But for the cards with Samsung memory, the value at A992 is FF which is -1 X 6.25 or -6.25mv, so something looks off. Do different memory versions of the card have different default offset values? Or is the location different?
Any help/guidance would be appriciated.
Seems like the samsung one doesn’t have global offset.
Stock roms with global offset have either ’03’ +18.75mV value or ’04’ +25mV as VDDC offset. I’ve never seen something else, or rather negative offset.. and i’ve opened up a lot of them 😉 ‘But correct me if i’m wrong..’
Greetings.
113-D0090101_103.rom
Stock at +37.5mV, that’s when i decided to use literal offset, rather than writting -125 in the vbios name for F0 when stock was 04.
Published at Sat, 25 Mar 2017 16:06:41 +0000
[wpr5_ebay kw=”bitcoin” num=”1″ ebcat=”” cid=”5338043562″ lang=”en-US” country=”0″ sort=”bestmatch”] Policy Prescription State of the Net 2015 at the Newseum, Washington DC on January 27 2015.
By Internet Education Foundation on 2015-01-27 13:20:50
FinTech’s Influence in Asian Markets Grows Several Asian countries are experiencing a growing effect of the fintech revolution that has swept across economies as innovative solutions pave the way for improving services and changing how […]
What is United bitcoin and How To Claim It? Remember to hit the SUBSCRIBE and NOTIFICATIONS button now. Join Our Telegram Chat =================== https://t.me/CryptoGrinders Website ================== https://www.CryptoGrinders.com Join Our Facebook ================ https://www.facebook.com/groups/CryptoGrinders/ Follow Us on […]
Coin Center is a non-profit in Washington DC that focuses on research and advocacy issues facing public blockchain networks like bitcoin and Ethereum. Their aim is to protect users and foster innovation through achieving sound policies and regulations.
Director of Research Peter Van Valkenburgh joined us to discuss the work of the center and the most pressing regulatory issues facing the industry today.
