Messages

226

GPU Compute / Accelerators / Re: Blackbird Radeon RX580

« on: November 08, 2021, 12:38:16 pm »

What are your kernel command line options? According to https://bugzilla.kernel.org/show_bug.cgi?id=200695 some people have had trouble with amdgpu.dc=1 (setting it to =0 seemed to fix it), though that problem seems to be somewhat old. There are a lot of comparable WX7100 OpenPOWER systems out there which should be the same generation, so I would expect this to be a more widespread problem (but I haven't upgraded my workstation to 35 yet either, planning to do the BMC-only Blackbird this week).

227

Operating Systems and Porting / Re: [NEWS] Fedora 35 is out folks

« on: November 03, 2021, 08:25:09 pm »

The problem was the lack of SIMD in one of the libraries. That should be fixed by now.

I'll be updating probably this weekend-ish, so I'll advise.

228

General Discussion / Re: Learning POWER9 assembly

« on: November 02, 2021, 07:56:00 pm »

32-bit assembly is a start but it will only get you part of the way -- you should really start with 64-bit and just think in those terms. Fortunately PowerPC was very forward looking from the beginning and 64-bit instructions were specified even from the days of the 601: my best reference for Power ISA is a very old book called Optimizing PowerPC Code by Gary Kacmarcik, supplementing it with the Power ISA 3.0b documentation and the ppc64le ELF v2 ABI specification. I have a physical copy of OPPCC but there are PDF copies around.

229

GPU Compute / Accelerators / Re: AMD OpenCL / ROCm

« on: October 24, 2021, 06:18:33 pm »

The first one you may not actually need. Note that the ARM version is in fact unimplemented. The return address is always in the link register in ABI-compliant code for both ARM and Power, but in x86(_64) it's on the stack. Similarly, Os::cpuid and Os::xgetbv seem only to compile on x86_64, not ARM. I'd just make sure your logic follows ARM (and have appropriate assertions to enforce this for unimplemented functions).

The memcpy situation is actually because the semantics changed between glibc versions. Here's an explanation: https://stackoverflow.com/questions/35656696/explanation-of-memcpy-memmove-glibc-2-14-2-2-5#35678441

230

Talos II / Re: Order processing time

« on: October 24, 2021, 06:11:09 pm »

Probably weeks or less though I don't know for certain. However, from personal experience, they don't start the RMA clock until it actually ships, so don't worry about it being out of warranty by the time you get it.

231

GPU Compute / Accelerators / Re: AMD OpenCL / ROCm

« on: October 22, 2021, 07:58:15 pm »

Can you post a couple links to the specific places in the source you're looking at?

Modern OpenPOWER is a superset of PowerPC, so any 64-bit PowerPC instruction reference will broadly apply. POWER9 is compliant to ISA 3.0. https://openpowerfoundation.org/?resource_lib=power-isa-version-3-0

232

Talos II / Re: Order processing time

« on: October 22, 2021, 07:55:19 pm »

No, though they're both good signs. In Stock means they literally have it in the warehouse right now, in a box, ready to go. Full Production means they're being made now (not merely to order) and will be in the warehouse.

233

Talos II / Re: Order processing time

« on: October 22, 2021, 07:25:55 pm »

It's US to US, so if it's in stock my experience is they've been good with getting it out (three systems here).

234

General CPU Discussion / Re: max memory speeds

« on: October 22, 2021, 07:10:29 pm »

As a general rule 3200MHz should run fine at 2666MHz, but I don't see any 3200MHz RAM on https://wiki.raptorcs.com/wiki/POWER9_Hardware_Compatibility_List/Memory . That doesn't mean it doesn't work, but you'd be a pioneer.

Also, I want to correct a miscount in my prior post: each pair of DIMM slots in the T2/T2 Lite is a channel, so the T2/T2 Lite have 4 per CPU. However, the pair of DIMMs in that pair of slots counts as one, so it's still 1:1. The Blackbird, however, is indeed one channel per slot.

235

General CPU Discussion / Re: POWER9 water cooling kit

« on: October 20, 2021, 12:40:00 pm »

No, I saw that; just checking it didn't change. Thanks!

236

General CPU Discussion / Re: max memory speeds

« on: October 19, 2021, 04:39:02 pm »

My understanding (perhaps Raptor can clarify) is that both are right, in a manner of speaking. You get the full 2666MHz with a single DIMM per channel, 2400 for 2, 2133 for 4. However, the controller for each processor has 8 channels and no Raptor system has more than 8 DIMM slots per CPU, so it's physically impossible to get multiple DIMMs on one channel. On a large system with more than 8 DIMM slots per CPU socket, however, it's possible.

237

General CPU Discussion / Re: POWER9 water cooling kit

« on: October 19, 2021, 04:33:15 pm »

Are you planning to sell fluid as well, or if not, what's your specific recommendation? How good is the mounting pressure on these?

238

Applications and Porting / Re: Porting Godot 4 to POWER9 and the Libre-SOC.

« on: September 20, 2021, 06:00:10 pm »

I'm surprised Embree works on the M1, given that it's an Intel product (unless you mean not natively, i.e. through Rosetta 2).

239

GPU Compute / Accelerators / Re: AMD rendering issues with Debian Bullseye

« on: August 04, 2021, 10:46:18 pm »

Do you see anything on the serial port, either connecting directly to it, or from the web BMC interface?

240

GPU Compute / Accelerators / Re: AMD rendering issues with Debian Bullseye

« on: July 24, 2021, 11:27:01 pm »

What happens if you try to mount the media in the Petitboot shell? Do you see files?