[mythtv-users] New installation, choppy video (not DMA) help request

[Dan]

This message is in reply to "Marcone at xs4all" via gossamer-threads.com.
I initially subscribed to digests and switched this AM since people were
responding pretty quickly.  I didn't get the message but saw it on the
archive.  Apologies for thread-busting....

>Have you actually measured the throughput of your disk? I set up a new 
>machine recently and at first it was using the "generic IDE" driver, 
>which caused extremely poor disk performance and high CPU usage while 
>accessing the disk, even though hdparm showed DMA being used. After 

I ran hdparm -t but am unsure if this is a sufficient test or
how to interpret the numbers.  They are below:

[root at localhost log]# hdparm -tT -i /dev/hdd

/dev/hdd:

 Model=WDC WD400BB-75CAA0, FwRev=16.06V16, SerialNo=WD-XXXXXXXXXXXX
 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq }
 RawCHS=16383/16/63, TrkSize=57600, SectSize=600, ECCbytes=40
 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=78125000
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4 
 DMA modes:  mdma0 mdma1 mdma2 
 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 
 AdvancedPM=no WriteCache=enabled
 Drive conforms to: device does not report version: 

 * signifies the current active mode

 Timing cached reads:   4356 MB in  2.00 seconds = 2177.86 MB/sec
 Timing buffered disk reads:  142 MB in  3.03 seconds =  46.83 MB/sec

I don't know if cached/buffered covers the full range of relevant
drive performance metrics for MythTV.