My 40-wire SATA DVD-RW & FC16 LiveCd

[tashirosgt]

According the FC 16 LiveCd, my SATA DVD-RW is set to UDMA/33 because it has a 40-wire cable.

The output of dmesg:

ata5.00: ATAPI: TSSTcorp CDDVDW SH-S223Q, SB03, max UDMA/100
ata5.00: limited to UDMA/33 due to 40-wire cable
ata5.00: configured for UDMA/33

Of course, the DVD-RW is on a SATA controller and connected by a SATA cable. The controller is set to the "IDE" mode (since, as I mentioned in another thread, DVD-RWs apparently don't work on controllers set to the better AHCI mode).

Is it the normal for SATA DVD-RWs to be set to the UDMA/33 mode? Would it actually help their performance if they were set to UDMA/100?

[sonoran]

Originally Posted by tashirosgt

Is it the normal for SATA DVD-RWs to be set to the UDMA/33 mode? Would it actually help their performance if they were set to UDMA/100?

My Sony Optiarc drive gets configured to UDMA/100, in dmesg.log:

ata5.00: ATAPI: Optiarc DVD RW AD-7280S, 1.01, max UDMA/100
ata5.00: configured for UDMA/100

Interestingly, the wikipedia entry on AHCI has a link to this Fedora Forum thread:
http://fedoraforum.org/forum/showthread.php?t=202286

Note that my BIOS has SATA configuration set to "Native IDE", not "AHCI" - it came that way and I haven't messed with it. SATA HD and DVD read-write speeds are both pretty good.

[DBelton]

Same thing here. Mine gets configured to UDMA/100

[    0.651323] ata3: SATA max UDMA/133 cmd 0xd080 ctl 0xd000 bmdma 0xc800 irq 19
[    0.651386] ata4: SATA max UDMA/133 cmd 0xcc00 ctl 0xc880 bmdma 0xc808 irq 19

[    0.822378] ata4.01: NODEV after polling detection
[    0.841254] ata4.00: ATAPI: TSSTcorp CDW/DVD TS-H493A, CD07, max UDMA/100
[    0.863152] ata4.00: configured for UDMA/100

[tashirosgt]

Same thing here. My OptiArch AD-7240 S gets configured at UDMA/100

That's under FC 12.

Both on this system and the one mentioned in the OP the SATA controller for the DVD-RW is set to IDE mode.

Does anyone have a Samsung SH-S223 that got configured to UDMA 100?

[george_toolan]

Would it actually help their performance if they were set to UDMA/100?

Not at all. Your burner isn't faster than 33 MB/sec ;-)

If you can you should enable AHCI in your BIOS setup, because advanced sata features like NCQ don't work in ide compatibility mode.

[tashirosgt]

Originally Posted by george_toolan

If you can you should enable AHCI in your BIOS setup, because advanced sata features like NCQ don't work in ide compatibility mode.

I 've enabled it on the SATA controller for the hard drive, but the Samsung DVD-RW won't work on a controller in the AHCI mode. Anyone have a DVD-RW working in the AHCI mode?

[PabloTwo]

Originally Posted by tashirosgt

Anyone have a DVD-RW working in the AHCI mode?

Yes, I do. My BIOS let's me choose either IDE, AHCI or RAID mode, which affects both SATA controllers (SATAII and SATA3). I have AHCI set.

[    0.882465] ata4: SATA max UDMA/133 abar m2048@0xfa205000 port 0xfa205280 irq 45
[    1.187068] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[    1.188774] ata4.00: ATAPI: ASUS    DRW-24B1ST, 1.01, max UDMA/100
[    1.189494] ata4.00: configured for UDMA/100

[tashirosgt]

Originally Posted by PabloTwo

Yes, I do.

Tell me the model of that DVD-RW and I'll put it on my shopping list! I couldn't tell from your output.

[DBelton]

According to the output he posted above, it appears this is the drive he's got:

http://www.newegg.com/Product/Produc...82E16827135204

An Asus DRW-24B1ST

[sonoran]

On george_toolan's recommendation I switched my BIOS to AHCI - so far so good. Everything works.
dmesg:

[ 0.927138] ahci 0000:00:11.0: version 3.0
[ 0.927222] ahci 0000:00:11.0: irq 42 for MSI/MSI-X
[ 0.927319] ahci 0000:00:11.0: AHCI 0001.0100 32 slots 4 ports 3 Gbps 0xf impl SATA mode
[ 0.927322] ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio slum part ccc

The only obvious change is a message at the start of boot: "AHCI Drive Init" followed by about a 3 second pause, then a list of my two HDs and the DVD drive. The Sony DVD is configured as before, UDMA/100.

Subjectively (no actual testing), it appears the 3 GKrellM meters for my cpu cores are registering noticeably less activity when playing a DVD with vlc, maxing at 2-4% rather than the 6-7% they used to jump to.

Those few seconds of additional boot time would be a small price to pay for greater overall system efficiency (we watch a lot of movies). Thanks tash & george, et al.

(Drive is a Sony Optiarc DVD RW AD-7280S, about $20 US including shipping from Newegg)