Did you ever think about running a separate mining instance for your crappy 570's or just throwing them away?

EDIT 9/29/2018 @ 8:07 PM CDT: This problem with very low hash rates is only on a HP Z400 System with an Intel X5660 processor. On my other system which has 4x Vega 56's and an Intel i3-4340 the hash rate is 7331 H/s for V8 and 7585 H/s for V7. So V8 is 96.7% of V7 or a 3.3% decline which is better than 7% quoted.

The Intel Xeon X5660 is a Westmere Microarchitecture whereas the Intel i3-4340 is Haswell Microarchitecture.

http://www.cpu-world.com/CPUs/Xeon/Intel-Xeon%20X5660%20-%20AT80614005127AA%20(BX80614X5660).html
http://www.cpu-world.com/CPUs/Core_i3/Intel-Core%20i3-4340.html

Cast XMR's Support for the Monero V8 Network upgrade which introduces a new CryptoNight variant CryptoNightV8 aka CNv2 is broken badly for Vega 56's if they are using CPU's from the Westmere Microarchitecture. The quoted 7% hash rate drop is actually 62.7% for Vega 56's.


I have just tested Cast XMR Version 1.5.0 (2018/9/27) on my system with 2x Vega 56's and the hash rate decrease is drastic as in 1442 H/s for V8 vs 3845 H/s for V7. That works out to be only 37.7% of the V7 hash rate or a decrease of 62.3% not the 7% stated.

I used --algo=10 for CryptoNightV8 (CNv2) and the killallasics.moneroworld.com:7777 port for testing.

On V8 I am only getting 1442 H/s on the two Vega 56's (715 H/s GPU0 and 737 H/s GPU1). While mining V8 the individual hash rates jumps all over the place from 847 to 568 on each card.

Had computation error, i lowered Ram clockspeeds by 50 mhz , not related to core clocks.

worked.

So just a question, before i usually used HBCC and blockchain drivers on windows 10 (1600 or 1700 build win10 build)  and i got around 1440 h/s in cryptonight heavy for RX Vega 56

But today, everytime i try blockchain driver i get around 1150 h/s  and the adrenalin ones gives around 1290 but i found one that does 1320 and it worked across several windows builds.


My problem is that, is 1450 only for V56 flashed to V64?  because im not flashed, i did test it a year ago but oh well it had a power issue where it kept increasing power whenever under load until it throttled during release month.

Which drivers are people using with RX Vega now and are you using HBCC ? Have you flashed V56? for Cryptonight heavy 

Hi,

an Cast XMR update is available. Please update your miners before 18th October if you are into Monero.

Also there is now a Cast XMR for Ubuntu beta.

Regards,
Glph3k


Cast XMR Version 1.5.0 (2018/9/27)

- Support for the Monero V8 Network Upgrade which introduces a new CryptoNight variant CryptoNightV8 aka CNv2. The Monero V8 update is scheduled for 18th October. In case you are mining Monero make sure to update Cast XMR before that date. Also make sure that the algo for Monero is not explicitly set to CryptoNightV7 but set to auto detect with --algo=-1 to automatically switch from CryptoNightV7 to CryptoNightV8 when the upgrade is happening. Please also note that the CryptoNight V8 algo has added complexity which decreases the hashrate up to 7% for Vega GPUs.

Download Cast XMR 1.5.0 for Windows (64bit)

SHA256 hash of cast_xmr-vega-win64_150.zip:
7e1a3495b2794056fe487736970ab10fd2d3010412a8a3c0c92780a693a2fcfa

A beta version of Cast XMR for Linux is available here:

Download Cast XMR 1.5.0 (beta) for Ubuntu 16.04/18.04

Hi,

this is a known issue (related to some mainboard chipsets?). The cure seems to install the AMD drivers version 18.5.1 (if that does not help version 18.6.1.).

Independent form the hash rate drop. Please use the "--algo=-1" switch or leave the algo setting out completely to make the automatic switch from CryptoNighV7 to V8.

Regards,
glph3k

I would also recommend 18.5.1. Later drivers are not that stable or have a lower performance.

Did you test V8 with a testnet pool like http://killallasics.moneroworld.com/ ? Submitting V8 shares to the current chain will give "share above target" error.