[mythtv-users] OT: Troubleshooting write speed problems

nasa01 at comcast.net nasa01 at comcast.net
Mon Aug 20 10:23:54 UTC 2007


I know, this is way off topic, but I figured there must be a lot of smarter people on the list than I.
I was troubleshooting what I thought was a network issue, when I decided to test my harddrive speeds... Looking at the results, my aim how changed.  How do I fix these write speed issues?  Info follows:

 I have three machines (Main, mythtv, MythTV_Server).  All machines are running a version of mandrake (later than 2006).  

Kernel:  2.6.22-rc1

GIGABYTE GV-NX73G256D-RH GeForce 7300GS 512MB(256MB on Board) GDDR2 PCI Express x16 Video Card 
WINTEC AMPO 1GB (2 x 512MB) 240-Pin DDR2 SDRAM DDR2 533 (PC2 4200) Dual Channel Kit Desktop Memory Model 3AMD2533-1G1K-R 
AMD Athlon 64 X2 3800+(65W) Windsor 2.0GHz Socket AM2 Processor 
Seagate ST3300831A ATA Drive
MSI K9N Platinum Socket AM2 NVIDIA nForce 570 Ultra MCP ATX AMD Motherboard 

hdparm -v /dev/hda

multcount = 16(on)
IO_Support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readahead = 256 (on)
geometry = 19457/255/63, sectors = 312581808, start = 0

dd results very similar to dd results for hda on MythTV_Server

Kernel:  2.6.17-13mdv

HighPoint Technologies, RocketRaid 1740 
DFI Infinity RS482 Motherboard 
CPU AMD|A64 3400+ 2.2G 939 
756M generic ram 
4x320G Harddrives in Raid 5 

hdparm -v /dev/hda (same as mythtv, except for geometry)
...will update hdparm -v /dev/sda later (would this be usefull?)

hdparm -tT /dev/sda

 Timing cached reads:   2432 MB in  2.00 seconds = 1214.37 MB/sec
 Timing buffered disk reads:  184 MB in  3.01 seconds =  61.05 MB/sec

time dd if=/dev/zero of=./test.tmp bs=1024k count=4000
2066+0 records in
2066+0 records out
2166358016 bytes (2.2 GB) copied, 129.33 seconds, 16.8 MB/s
Command terminated by signal 2
0.02user 19.98system 2:09.49elapsed 15%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (1major+275minor)pagefaults 0swaps

sync; time bash -c "dd if=/dev/zero bs=1024k count=20 48 of=/mnt/Raid/testspeed; sync"
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 63.3346 seconds, 33.9 MB/s
0.01user 4.42system 1:13.53elapsed 6%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (4major+943minor)pagefaults 0swaps


Main machine is an AMD 64 X2 3800+
with a WD Raptor HD

dd results for comparison....

2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 35.5994 seconds, 60.3 MB/S



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