X speed problem

bukharin · Posted: Sun May 02, 2004 9:30 am Post subject: X speed problem

Hi everyone,

I'm a newbie to Gentoo but have been using linux on the desktop for a few years. I've just switched from Mandrake 9.0 because I wanted smoother updates, and felt like a change in general. So far, I'm very impressed with Gentoo!

Unfortunately, X in Gentoo is a lot slower than in Mandrake. For example, fast scrolling using pageup/pagedown in Mozilla is a lot less smooth; and when minimising/maximising a window, it's relatively easy to see the separate window components being drawn, whereas in Mandrake it's not. I can't really understand why this would be, but it's really annoying!

What I've tried so far:
- checked that DMA is enabled for my hard disks, and benchmarked them with hdparm -tT - same results as in Mandrake. Actually I initially stuffed this up, and got a major performance boost when fixed
- emerged nvidia-kernel and nvidia-glx (version 1.0.4496)
- checked that DRI is working - it is (glxgears gives framerates over 3000) - so presumably the nvidia kernel module is working properly
- checked that AGP is working - I'm using AGPGART at 4x, same as in Mandrake
- tried using my Mandrake XF86Config - no improvement (though I had to comment out 'FontPath "unix/:-1"' for that config file to work in Gentoo)
- made sure there are no processes running in the bg that are consuming resources

I'm kind of stuck now. I don't know exactly where to look next for potential problems. A couple of ideas that I have are
(1) is it a kernel misconfiguration? I'd appreciate any suggestions as to anything I need to look out for in my kernel config
(2) is it something to do with Gentoo using antialiased fonts, compared with Mandrake's non-antialiased ones? (old version of Mandrake, remember!). Have others noticed much of a performance hit when switching from non-antialiased to anti-aliased fonts?
(3) is it in fact a system-wide problem (like the DMA problem was), which is simply more noticeable in X? If that's the case, where (apart from DMA) should I be looking?

Any other ideas? Are there any objective benchmarks for X (or the overall system) that I could try, to help isolate the problem?

I'm happy to post my XFree86.0.log, XF86Config, kernel config or whatever people may think is relevant.

As you can imagine, this is quite frustrating. At the moment I'm dual-booting with Mandrake, because I really don't want to take an obvious performance hit; but I'd really like to change over completely to Gentoo.

Thanks for any help that people can offer,
bukharin

Little Nemo · Posted: Sun May 02, 2004 11:23 am Post subject:

I suspect it has something to do with font handling, too. I understand you're not using a font server (xfs?) with Gentoo, but you do with Mandraka?

I have FontPath

bukharin · Posted: Sun May 02, 2004 12:22 pm Post subject:

Thanks Nemo.

I didn't actually realise that my Gentoo install had xfs until I read your post! I've just tried using xfs instead of the hardcoded font locations in XF86Config, and it made no difference. I also tried commenting out every font location that I could - again, no difference. Finally, I tried xfs using both -1 and 7100 as its listening ports - again, no difference...

So it looks as though that's not the problem.

Seeing as X needs to talk to apps via TCP, I also checked that support for Unix domain sockets was enabled in my kernel (it is), and that my routing table and /etc/hosts file were correctly set up for localhost. I'm pretty sure they are; these are the relevant sections:

/etc/hosts:

nempo · Posted: Sun May 02, 2004 1:04 pm Post subject:

Try using the mozilla-bin ebuild instead of the 'standard' ebuild, ie. 'emerge mozilla-bin' instead of 'emerge mozilla'.

The self-compiled version has been known to come with a few slowdowns due to some special cflags.
_________________

Little Nemo · Posted: Sun May 02, 2004 1:06 pm Post subject:

NeddySeagoon · Posted: Sun May 02, 2004 1:12 pm Post subject:

bukharin,

Some distros run X with a nice of -10, RedHat was one.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

bukharin · Posted: Sun May 02, 2004 1:22 pm Post subject:

nempo - your post reminded me that in Mandrake, I was using the precompiled 1.6 binary from mozilla.org. Tried installing that same binary in Gentoo - same problem.

Anyway, I'm pretty sure it's not just a Mozilla problem - it's just that Mozilla is a little slower than my other apps, so it's easier to notice the problem with Mozilla. Another app that displays the slowness is kmail - I have over a thousand messages in my main inbox, and scrolling through them is noticeably slower in Gentoo than Mandrake. And it's not just fonts; eg juk displays a popup message over kicker at each track change, and when that popup message disappears, the rest of kicker reappears in sections rather than being instantly replaced (I only notice this when I click on the message to make it disappear, so that I can access kmix).

The reappearing in sections, in particular, is what made me think of VNC and slow network connections. But I can't see any reason that this should apply to my system. I've tried "ifconfig down eth0" to make sure that packets weren't going further than this computer, to no avail.

I'm quite sure you're right, Nemo, that it's not a Gentoo problem. I rather suspect that something's not quite configured correctly. I wouldn't be surprised to find a kernel misconfiguration (a la DMA), since that's what I'm probably least expert at - OTOH I can't think of anything I've missed.

I guess what I really need is some kind of X benchmarking tool - and probably a general system benchmarking tool/tools as well - to actually isolate where the problem lies. Any suggestions, people? Because really, anything that slows down the system as a whole could cause this kind of problem...

- NEO - · n00b Joined: 16 Aug 2003 Posts: 32 Location: Denmark

After a total reinstall of Gentoo from scratch I see exact the same problem here.

My kernel config is exact the same as before the problem occured.

Though my nvidia card is changed from DDR to FX5200.

I'm using the latest nvidia--kernel 5336-r3.
_________________
/Neo
...because I believe in something...

gatiba · Guru Joined: 01 Sep 2002 Posts: 434

I noticed the same graphics slowdown on gentoo...

For example: if i resize right and left with the mouse the mozilla's sidebar, i can notice it redraw slower than Suse or Mandrake...

Sorry for my english...

bukharin · Posted: Fri Jun 04, 2004 11:15 pm Post subject:

Thanks for your comments, NEO and gatiba. Over the weekend I also did a stage 1 reinstall of gentoo and still have exactly the same problem.

I tried booting into Mandrake using my gentoo kernel, and it was fast. So I'm pretty sure it's not the kernel.

NEO - were you using gentoo before, but after reinstalling it's slower? That's very strange isn't it? Either the newer packages are slower in some way, or do you think it could be something to do with our USE flags? I was thinking of recompiling X, and/or KDE, with much tighter USE flags...

I'm using basically the latest version of every package (obviously), and this is my make.conf:

headache · Apprentice Joined: 26 May 2004 Posts: 226

Try to aff the correct hostname and ip address to your /etc/host file.

I see that you only have:

- NEO - · n00b Joined: 16 Aug 2003 Posts: 32 Location: Denmark

bukharin · Posted: Sun Jun 06, 2004 5:06 am Post subject:

headache: unfortunately, I don't think it's as simple as that, because (1) I think my /etc/hosts is correct, (2) I copied /etc/hosts from the Mandrake installation, which works fine, and (3) it's slow even if I disable the network...

bukharin · Posted: Thu Jun 10, 2004 10:26 am Post subject:

gatiba: are you also using an nvidia card?

gatiba · Guru Joined: 01 Sep 2002 Posts: 434