Mailinglist Archive: opensuse (5130 mails)

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Speed Issues with 9.3 vs 10.0 on x86_64 arch? Or What?
  • From: Shaun Q <shaun@xxxxxxxxxxxx>
  • Date: Tue, 9 May 2006 14:16:55 -0700 (PDT)
  • Message-id: <Pine.BSO.4.63.0605091401500.32243@xxxxxxxxxxxxxx>
Hey everyone --

First of all, I apologize if this is an inappropriate forum for this... but perhaps someone has an idea...

So, we installed a new cluster here with some Athlon 64 machines... and we're finding that these new machines are quite a bit slower than our old AMD64 test machine...

So I ran lmbench 3.0 on these machines to see if I could find some of the bottlenecks -- and came up with the following:

Two machines were tested -- CT4 and CT115:

CT4 is an opteron 1.8 with a 9.3 normal install. CT115 is an Athlon 64 3400+ (clock at 2400 Ghz) with a diskless install (and we've tried the same hardware with a normal non-diskless install and the results are simular...)

So some of the basic results were what we'd expect... numbers were better on CT115:
Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host OS Mhz null null open slct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
ct4 Linux 2.6.4-5 1786 0.10 0.39 4.46 5.09 15.2 0.31 1.22 115. 480. 2886
ct115 Linux 2.6.16. 2410 0.07 0.13 1.42 2.17 9.29 0.19 1.07 113. 393. 4223

Float/Int, etc.. numbers blew the CT4 machine too...

But then we get to some of the context switching tests for example:
Context switching - times in microseconds - smaller is better
-------------------------------------------------------------------------
Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw
--------- ------------- ------ ------ ------ ------ ------ ------- -------
ct4 Linux 2.6.4-5 0.5200 0.6600 5.2300 2.3500 5.7400 2.48000 18.0
ct115 Linux 2.6.16. 0.5400 0.5800 3.1800 1.8900 26.0 3.83000 49.5

After we get to 8p/64K and above, the numbers are quite bad as you can see...
And the Bcopy and memory numbers:

*Local* Communication bandwidths in MB/s - bigger is better
-----------------------------------------------------------------------------
Host OS Pipe AF TCP File Mmap Bcopy Bcopy Mem Mem
UNIX reread reread (libc) (hand) read write
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
ct4 Linux 2.6.4-5 1077 1149 520. 1136.2 2453.4 938.2 938.6 2427 1360.
ct115 Linux 2.6.16. 1798 2062 269. 259.3K 1489.2 391.6 389.4 1483 578.8


So, where should I be looking here in order to get these machines up to where they should be? Anyone have any ideas to help me overcome this issue? Is it hardware or software? Would a memory issue cause this? Even though they both have 1Gb PC3200 memory, CT4 has ECC memory and CT116 just has regular el-cheapo Corsair memory. Would that make a difference here?

Thanks!
Shaun

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