AMD A10-7850K Kaveri: The Linux Introduction

[zanny]

With that said, who the hell cares what it can do under windows I want to see this puppy unleashed with some nice optimization flags and unleashed in LINUX.... Of course, the driver problem seems to be holding that up.

A gpu without a working driver is just a bunch of idle transistors under a heatsink. Gotta hold AMD responsible for producting both the hardware and the software to use it.

Anywho, I think that even the anandtech results show promise - in terms of gpu performance, it takes Iris Pro (which is only really available on $250+ cpus) to keep up with any AMD part. For first generation Steamboxes, if AMD could ever get this thing working acceptably under radeon or Catalyst, it wouldn't even be close to go with the amd builds if you want to budget it around $200 - 300 without a discrete gpu. And then you also have to consider, how many really demanding games are there under Linux besides Metro? Most of what you'd play locally would run at 1080p/60 just fine on a top end Kaveri assuming Linux performance near parity with the Windows. Though I guess thats asking a lot.

[theghost]

Thx Michael for the detailed review.

I thought about getting an A10-6800k but now that the Kaveri is released...
Looks good for a small case, self build Steambox.

Is it also possible to run the CPU with a discrete GPU ? So it would be possible to power up the CPU if better games hit Linux as well.

[zanny]

Thx Michael for the detailed review.

I thought about getting an A10-6800k but now that the Kaveri is released...
Looks good for a small case, self build Steambox.

Is it also possible to run the CPU with a discrete GPU ? So it would be possible to power up the CPU if better games hit Linux as well.

Of course you can use this processor with a discrete gpu, but that defeats the purpose of it. It would make more sense to get an fx chip and discrete gpu than an apu + gpu, or just get one in the athlon line that has the gpu disabled (last gen parts like the 755 were only like $70 for a reasonable quad core at 4ghz). Also note we are likely to never see hybrid graphics supported on Linux, unless the Mesa driver devs coordinate a way to share kernel workloads between drivers.

[Veerappan]

This was with the Mesa 10.0.1 driver packages in Ubuntu 14.04. Lastly, I tried adding in Mesa from Git master (Mesa 10.1-devel) but here when launching the X.Org Server and going with GLAMOR for 2D acceleration, there was a segmentation fault.

Yeah, I've run into that myself with mesa-git. You can work around it by renaming /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so to /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so.bak and then creating a symlink from /usr/local/lib/dri/radeonsi_dri.so to /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so. Substitute your mesa prefix as appropriate.

libglx as packaged by ubuntu really doesn't like to use a self-compiled mesa for radeonsi at the moment, and I haven't figured out the exact compile options to correct it yet.

Also, xorg-edgers for 13.10 already includes llvm-3.4 and everything needed to run radeonsi, and it looks like the xf86-video-ati in xorg-edgers is new enough that the kaveri PCI IDs might be supported.

I just did a fresh Ubuntu 13.10 install on my desktop last week and then installed xorg-edgers (Radeon 7850 here), and everything worked correctly. Glamor/mesa/etc. I'm currently running kernel 3.13rc7, and that combination of software seems to be working quite well.

Once we fix up some of the glamor fallback performance issues, things will be even better.

I would love if you managed to attempt xorg-edgers and an updated kernel in an upcoming article (I'm assuming that at some point you'll be doing an OSS vs Catalyst comparison for Kaveri or another older SI card).

[Delgarde]

What I don't get is how new chipsets / processors have support in the kernel often months in advance and will run out of the box on even outdated LTS Ubuntu releases or CentOS, but gpus (in general, Intel does this with their new stuff too, cutting it too close to the last minute) don't see drivers until usually after their release, especially Mesa ones, and definitely not in advance enough to guarantee even the latest Ubuntu / Suse / Fedora / etc releases work with them.

Because support for new CPUs and chipsets is generally trivial - they're all basically compatible with standards, so it's not really about support, and more about optimisation and taking advantage of new features. Whereas GPUs are effectively all unique - a new model might share some design elements with a predecessor, but much larger changes are needed to make it actually work.

[curaga]

A gpu without a working driver is just a bunch of idle transistors under a heatsink. Gotta hold AMD responsible for producting both the hardware and the software to use it.

Anywho, I think that even the anandtech results show promise - in terms of gpu performance, it takes Iris Pro (which is only really available on $250+ cpus) to keep up with any AMD part.

Regarding the Anandtech review and Iris Pro, the Iris had the worst minimum FPS of all tested cards in some games, and only average in others. While the Kaveris were at the top of min fps in all games.

So for smoothness they are in the lead.

[bridgman]

I just did a fresh Ubuntu 13.10 install on my desktop last week and then installed xorg-edgers (Radeon 7850 here), and everything worked correctly. Glamor/mesa/etc. I'm currently running kernel 3.13rc7, and that combination of software seems to be working quite well.

FYI I just tried this on my engineering sample Kaveri box -- fresh 13.10 install plus xorg-edgers PPA -- and the open source stack came up fine when I rebooted after updating. Played Xonotic for a couple of minutes and that seemed OK too.

Really should have a newer kernel than the 3.11 that comes with Saucy, will update that next, but so far the open source stack seems to be working OK. For what it's worth, this is more in line with what we expected since we pushed initial Kaveri open source driver support back in Sept or Oct last year.

[Michael]

FYI I just tried this on my engineering sample Kaveri box -- fresh 13.10 install plus xorg-edgers PPA -- and the open source stack came up fine when I rebooted after updating. Played Xonotic for a couple of minutes and that seemed OK too.

Really should have a newer kernel than the 3.11 that comes with Saucy, will update that next, but so far the open source stack seems to be working OK. For what it's worth, this is more in line with what we expected since we pushed initial Kaveri open source driver support back in Sept or Oct last year.

Yeah I'll be trying xorg-edgers soon as the system frees up after reading post from another reader in this thread or the other one about custom Mesa builds being borked up on latest Ubuntu.

[oblivious_maximus]

45W on all Kaveris?

The configurable TDP feature works on any Kaveri APU but AMD only has optimized it for the low-end A8-7600.

Could someone elaborate on this part a bit?

The configurable TDP is definitely available on all Kaveri chips? But on the two higher end models if you put it into 45W mode the performance will tank way more than it would if it had been optimized? Should I not consider buying now if I want to run at 45W?

[jakubo]

Has AMD published any documentation/guidelines on how to program for HSA enabled chips? Or will AMD be doing the same mistakes as with 64bit computing...? IIRC linux-based distros were the first OSes to support 64 bit back then.