[mythtv-users] gt 240, fanless card .. issues

[John Drescher]

On Tue, Feb 2, 2010 at 10:46 AM, David Durham <david.durham.jr at gmail.com> wrote:
>> Now that you are experiencing the fantastic CPU savings of vdpau, you
>> may find that the cpu power saving configuration kicks in.
>> (cpufreq/powernowd/etc)
>>
>> With the CPU underutilised, the cpu speed drops to the lowest clock
>> rate, and (depending on your mobo/chipset/cpu) this can also slow the
>> bus (pci/pci-e/disk/memory etc).
>>
>> If you do experience stuttering, make sure you turn all power-saving
>> modes off and retest. I personally
>> have the cpu's drop to their lowest setting, while a friend finds
>> stuttering when the cpu speed drops
>> because their chipset also reduces (throttles?) PCI-E bandwidth.
>
> Is this typically a bios setting?
>

You can turn off power saving in the bios or in linux. In linux select
the performance governor.

> Actually I do experience stuttering, but only from drives connected to
> an external eSata enclosure (no problems with internal drives).  Here
> are what I think are the relevant specs:
>
> 04:00.0 RAID bus controller [0104]: Silicon Image, Inc. SiI 3132
> Serial ATA Raid II Controller [1095:3132] (rev 01)
>        Subsystem: Silicon Image, Inc. Device [1095:7132]
>        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
> ParErr- Stepping- SERR- FastB2B- DisINTx-
>        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
> <TAbort- <MAbort- >SERR- <PERR- INTx-
>        Latency: 0, Cache Line Size: 32 bytes
>        Interrupt: pin A routed to IRQ 16
>        Region 0: Memory at feaffc00 (64-bit, non-prefetchable) [size=128]
>        Region 2: Memory at feaf8000 (64-bit, non-prefetchable) [size=16K]
>        Region 4: I/O ports at dc00 [size=128]
>        Expansion ROM at fea00000 [disabled] [size=512K]
>        Capabilities: <access denied>
>        Kernel driver in use: sata_sil24
>
>
> $ sudo hdparm -tT /dev/sdh
>
> /dev/sdh:
>  Timing cached reads:   7820 MB in  2.00 seconds = 3913.46 MB/sec
>  Timing buffered disk reads:   40 MB in  4.31 seconds =   9.27 MB/sec
>

That is ridiculous. The buffered disk read should be 10 times that number..

John