Improving disk performance

[keith_leitch]

I'm sorry if we covered this already, but what is everyone's opinion of an ideal cluster size for the Live TV partition? I can see an argument for it benefitting from large clusters, like a recordings drive; however, I can also see an argument for simultaneous recording and playback requiring more limited seeks and therefore small clusters.

[ga_mueller]

We have covered this already... bigger is better, when you segregate the recording and OS drives, and record on the drive with the 64K clusters... yawn.

[keith_leitch]

We have covered this already... bigger is better, when you segregate the recording and OS drives, and record on the drive with the 64K clusters... yawn.

Yes, sorry to bore you...I know we covered it for recording drives, but it may not be quite the same matter for Timeshifted TV, as one is almost certain to be playing back in close physical proximity to the sectors that are recording. It strikes me that this may warrant smaller (though not tiny) clusters.

[whurlston]

I use my recording drive (64K clusters) as the LiveTV buffer drive as well. They are in effect the same thing. Timeshifting is no different than watching a program that is currently being recorded which I do frequently. In fact, I usually watch one of the 4-5 shows that are being recorded at that particular time which is much more seeking than just regular timeshifting.

[keith_leitch]

OK. Despite all of the discussion here, and all of the tweaking I've done as a result, my backups continue to take a ridiculously long time. It doesn't matter whether I use a backup program, 7-Zip, or just a straight Windows copy, external drive, straight Sata-to-Sata copy at 7200 rpm, etc., etc....350GB takes anywhere between 10 and 13 hours to copy from one drive to another. Please tell me this isn't normal.

Last I checked, my BIOS was showing all drives on UDMA 6. I will check again after this interminable copy is finished, but I'm confident that is the case.

I am simply trying to copy my data so that I can change the cluster size as discussed, then copy it back. It really shouldn't be a three-day proposition, should it? This also raises the fear the performance may not be what I expect while I am recording.

[whurlston]

If you right click the drive in device manager, does it show write cache as being enabled?

[keith_leitch]

If you right click the drive in device manager, does it show write cache as being enabled?

Thanks for the suggestion. Yes, write caching is enabled on all drives, except for one external.

I also vaguely remember that I can check the UMA transfer mode without rebooting, here, but I can't find that information now.

I've found it. DMA Ultra Mode 6 enabled on four devices; I have four drives. Ultra Mode 4 is enabled on one device, but I am assuming that is either the DVD drive or an old external hard drive.

However, I've noticed that my Direct Memory Access controller has no driver installed for it. Could this be an issue?

[keith_leitch]

Hmmm...in searching my motherboard CD for the DMA driver, I've discovered a program that makes a boot disk for the purposes of installing AHCPI. This must be why my system was crashing on setup every time I had this set in the BIOS.

However, my research indicates that the advantages are minor, and that I would have to completely reinstall Windows XP to implement them. Is this correct? If so, I don't think it is worth it, and regardless, I first need to find a solution to my speed problems under Ultra DMA.

[keith_leitch]

It's a bit early yet to be sure, but I found and ran the VBScript duplicated below. The author claims that Windows sometimes deactivated UltraDMA mode due to write errors, but that this deactivation may not show in system properties. After running this utility and rebooting, I copied a 6.2 GB file between the same two drives as before in 97 seconds. This is 63 MB/second, which is actually slightly quicker than the averages I have been researching.

I will see later if and how it affects the restore of the 350 GB copy I performed.

If this works, I intend to take out the dialog boxes and simply run this script from the batch file that HIP invokes upon suspend. It takes less than a second to run it.




' Visual Basic Script program to reset the DMA status of all ATA drives

' Copyright © 2006 Hans-Georg Michna

' Version 2007-04-04

' Works in Windows XP, probably also in Windows 2000 and NT.
' Does no harm if Windows version is incompatible.

If MsgBox("This program will now reset the DMA status of all ATA drives with Windows drivers." _
& vbNewline & "Windows will redetect the status after the next reboot, therefore this procedure" _
& vbNewline & "should be harmless.", _
vbOkCancel, "Program start message") _
= vbOk Then

RegPath = "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\"
ValueName1Master = "MasterIdDataChecksum"
ValueName1Slave = "SlaveIdDataChecksum"
ValueName2Master = "UserMasterDeviceTimingModeAllowed"
ValueName2Slave = "UserSlaveDeviceTimingModeAllowed"
ValueName3 = "ResetErrorCountersOnSuccess"
MessageText = "The following ATA channels have been reset:"
MessageTextLen0 = Len(MessageText)
ConsecutiveMisses = 0
Set WshShell = WScript.CreateObject("WScript.Shell")

For i = 0 to 999
RegSubPath = Right("000" & i, 4) & "\"

' Master

Err.Clear
On Error Resume Next
WshShell.RegRead RegPath & RegSubPath & ValueName1Master
errMaster = Err.Number
On Error Goto 0
If errMaster = 0 Then
On Error Resume Next
WshShell.RegDelete RegPath & RegSubPath & ValueName1Master
WshShell.RegDelete RegPath & RegSubPath & ValueName2Master
On Error Goto 0
MessageText = MessageText & vbNewLine & "Master"
End If

' Slave

Err.Clear
On Error Resume Next
WshShell.RegRead RegPath & RegSubPath & ValueName1Slave
errSlave = Err.Number
On Error Goto 0
If errSlave = 0 Then
On Error Resume Next
WshShell.RegDelete RegPath & RegSubPath & ValueName1Slave
WshShell.RegDelete RegPath & RegSubPath & ValueName2Slave
On Error Goto 0
If errMaster = 0 Then
MessageText = MessageText & " and "
Else
MessageText = MessageText & vbNewLine
End If
MessageText = MessageText & "Slave"
End If

If errMaster = 0 Or errSlave = 0 Then
On Error Resume Next
WshShell.RegWrite RegPath & RegSubPath & ValueName3, 1, "REG_DWORD"
On Error Goto 0
ChannelName = "unnamed channel " & Left(RegSubPath, 4)
On Error Resume Next
ChannelName = WshShell.RegRead(RegPath & RegSubPath & "DriverDesc")
On Error Goto 0
MessageText = MessageText & " of " & ChannelName & ";"
ConsecutiveMisses = 0
Else
ConsecutiveMisses = ConsecutiveMisses + 1
If ConsecutiveMisses >= 32 Then Exit For ' Don't search unnecessarily long.
End If
Next ' i

If Len(MessageText) <= MessageTextLen0 Then
MessageText = "No resettable ATA channels with Windows drivers found. Nothing changed."
Else
MessageText = MessageText & vbNewline _
& "Please reboot now to reset and redetect the DMA status."
End If

MsgBox MessageText, vbOkOnly, "Program finished normally"

End If ' MsgBox(...) = vbOk

' End of Visual Basic Script program

[Reddwarf]

Windows' copy function is rather slow, but there is a free utility you can install called TeraCopy. It "takes over" whenever you use the copy function in windows, and from my experience it is considerably faster, maybe because it is using double buffering.