SuSe-8.2 Speed reading DVD suddenly down
SuSe-8.2 I have read DVD on it for many months with MPlayer without problem. It is on /dev/sr0. There was speed problems and I must always go in Yast/Materials/DMA-IDE configuration to reset the right DMA mode (I just had the list of devices and I click-clicked to activate the DMA mode - stange for a DVD reader!). Now, I tried an external DVD reader on USB port and, suddenly, I can't read the DVD's with a reasonable speed anymore. In Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list. Must I do something with hdparm? -- Alain Barthélemy cassandre@bartydeux.be http://www.bartydeux.be Linux User #315631
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Saturday 2006-03-04 at 21:10 +0100, Alain Barthélemy wrote:
Now, I tried an external DVD reader on USB port and, suddenly, I can't read the DVD's with a reasonable speed anymore. In Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list.
There is no dma for usb drives. No way. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFECjjptTMYHG2NR9URAhQFAJoCkH1IsonM1eehitcdcYkpyRllOgCglnqt OxWTK3aLbRPBQ9CszmZscrc= =nXEh -----END PGP SIGNATURE-----
Carlos, On Saturday 04 March 2006 17:03, Carlos E. R. wrote:
The Saturday 2006-03-04 at 21:10 +0100, Alain Barthélemy wrote:
Now, I tried an external DVD reader on USB port and, suddenly, I can't read the DVD's with a reasonable speed anymore. In Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list.
There is no dma for usb drives. No way.
Isn't that a function of what hardware is incorporated into the system? Are you saying that no one makes a USB adaptor with DMA capability even now that there are so many high-speed and mass storage devices? You'd think there'd be a demand for such a thing. Randall Schulz
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Saturday 2006-03-04 at 18:07 -0800, Randall R Schulz wrote:
On Saturday 04 March 2006 17:03, Carlos E. R. wrote:
The Saturday 2006-03-04 at 21:10 +0100, Alain Barthélemy wrote:
Now, I tried an external DVD reader on USB port and, suddenly, I can't read the DVD's with a reasonable speed anymore. In Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list.
There is no dma for usb drives. No way.
Isn't that a function of what hardware is incorporated into the system? Are you saying that no one makes a USB adaptor with DMA capability even now that there are so many high-speed and mass storage devices? You'd think there'd be a demand for such a thing.
No, I didn't say that. The OP poster wanted to activate DMA for his DVD drive on the USB, the same way it is done for internal drives on the IDE bus, with hdparm or something similar. There is no such thing. It should be possible for the designers of usb controller chips to use dma... but that is a diferent thing. Anyway, the speed of the bus is limited and fixed, dma would not increase it. It would lower the overhead on the cpu, that's all. Note: Extracting from the wikipedia: ] USB supports three data rates. ] ] * A Low Speed rate of 1.5 Mbit/s (183 KiB/s) that is mostly used for ] Human Interface Devices (HID) such as keyboards, mice and ] joysticks. ] * A Full Speed rate of 12 Mbit/s (1.4 MiB/s). Full Speed was the ] fastest rate before the USB 2.0 specification and many devices fall ] back to Full Speed. Full Speed devices divide the USB bandwidth ] between them in a first-come first-served basis and it is not ] uncommon to run out of bandwidth with several isochronous devices. ] All USB Hubs support Full Speed. ] * A Hi-Speed rate of 480 Mbit/s (57 MiB/s). ] ] Though Hi-Speed devices are commonly referred to as "USB 2.0", not all ] USB 2.0 devices are Hi-Speed. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFECuZbtTMYHG2NR9URAoVxAJ9JbKyN9TpnRPfyrUCHtaef4ta/5wCgg5HL RbXSKe/qGCiVeaMO5UJtd/Q= =EWWf -----END PGP SIGNATURE-----
Carlos, On Sunday 05 March 2006 05:23, Carlos E. R. wrote:
The Saturday 2006-03-04 at 18:07 -0800, Randall R Schulz wrote:
On Saturday 04 March 2006 17:03, Carlos E. R. wrote: ...
There is no dma for usb drives. No way.
Isn't that a function of what hardware is incorporated into the system? Are you saying that no one makes a USB adaptor with DMA capability even now that there are so many high-speed and mass storage devices? You'd think there'd be a demand for such a thing.
No, I didn't say that.
Actually, you did. You said "There is no dma for usb drives. No way."
The OP poster wanted to activate DMA for his DVD drive on the USB, the same way it is done for internal drives on the IDE bus, with hdparm or something similar.
I see.
There is no such thing.
Yes. There's (currently) no USB counterpart to "hdparm".
It should be possible for the designers of usb controller chips to use dma... but that is a diferent thing. Anyway, the speed of the bus is limited and fixed, dma would not increase it. It would lower the overhead on the cpu, that's all.
Yes and no. It's true that the use of DMA versus programmed I/O doesn't change the characteristic of the device. But if the processor has to take an interrupt for every byte (or word) transmitted, then at the upper ranges of USB bus speeds, DMA would be necessary to permit the full bandwidth of the bus to be realized without saturating the CPU. Consider the Hi-Speed USB spec. That's 20% faster than FireWire 400. Do you think any of the first-generation FireWire interfaces used programmed I/O? 40+ million interrupts per second? Doubtful.
Note:
Extracting from the wikipedia:
...
Randall Schulz
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Sunday 2006-03-05 at 07:42 -0800, Randall R Schulz wrote:
Isn't that a function of what hardware is incorporated into the system? Are you saying that no one makes a USB adaptor with DMA capability even now that there are so many high-speed and mass storage devices? You'd think there'd be a demand for such a thing.
No, I didn't say that.
Actually, you did. You said "There is no dma for usb drives. No way."
The word "drives" is the key there, as compared with IDE drives. Ok, I didn't make myself clear enough. «I didn't mean that», is that ok? ;-)
The OP poster wanted to activate DMA for his DVD drive on the USB, the same way it is done for internal drives on the IDE bus, with hdparm or something similar.
I see.
There is no such thing.
Yes. There's (currently) no USB counterpart to "hdparm".
I assume that if the usb chip can use DMA, it would be set for every device plugged to the bus, not only for certain drives or devices separately.
It should be possible for the designers of usb controller chips to use dma... but that is a diferent thing. Anyway, the speed of the bus is limited and fixed, dma would not increase it. It would lower the overhead on the cpu, that's all.
Yes and no. It's true that the use of DMA versus programmed I/O doesn't change the characteristic of the device. But if the processor has to take an interrupt for every byte (or word) transmitted, then at the upper ranges of USB bus speeds, DMA would be necessary to permit the full bandwidth of the bus to be realized without saturating the CPU. Consider the Hi-Speed USB spec. That's 20% faster than FireWire 400. Do you think any of the first-generation FireWire interfaces used programmed I/O? 40+ million interrupts per second? Doubtful.
Granted. But you do not need one interrupt for every byte, because the bus can transfer data in blocks or batches. The device transmits a block to the controller chip (actually, it is the chip in the PC who does the fetching), which could be stored in a local memory in the chip (this bit I'm speculating, I don't know for sure), and when the block is finished it sets an IRQ for the CPU to handle and retrieve it. I don't know if it is done this way, but it is how I would design it if it were my job, and I do know there is a block mode transfer. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFEC4q7tTMYHG2NR9URApksAKCWUSgsOm5/mfVyHUvtY3vKKB+TkgCeJpGC DfPiuKJ0m9nvUpTf9N8r8nQ= =coyQ -----END PGP SIGNATURE-----
On Sunday 05 March 2006 14:23, Carlos E. R. wrote:
The OP poster wanted to activate DMA for his DVD drive on the USB, the same way it is done for internal drives on the IDE bus, with hdparm or something similar.
That wasn't what he said. He said after trying a USB CD drive, he could no longer see his IDE driver to enable DMA on it He may have meant something else, but that was what he said
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Sunday 2006-03-05 at 16:57 +0100, Anders Johansson wrote:
That wasn't what he said. He said after trying a USB CD drive, he could no longer see his IDE driver to enable DMA on it
He said: ] Now, I tried an external DVD reader on USB port and, suddenly, I can't ] read the DVD's with a reasonable speed anymore. In ] Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list. I understand he talks there about the external DVD on the USB. If it is otherwise, the paragraph need rewriting, IMO. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFEC2vttTMYHG2NR9URAkJUAJwPvWc52yPM9PXr2zV4d+pbbnTNWQCdELjr Moby3PoFGvVJoBXIKO9d74w= =NlHC -----END PGP SIGNATURE-----
On Sunday 05 March 2006 23:53, Carlos E. R. wrote:
The Sunday 2006-03-05 at 16:57 +0100, Anders Johansson wrote:
That wasn't what he said. He said after trying a USB CD drive, he could no longer see his IDE driver to enable DMA on it
He said:
] Now, I tried an external DVD reader on USB port and, suddenly, I can't ] read the DVD's with a reasonable speed anymore. In ] Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list.
I understand he talks there about the external DVD on the USB. If it is otherwise, the paragraph need rewriting, IMO.
He said:
] In Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list
Since USB isn't IDE, and therefore USB drives don't show up in an IDE list, he must mean he can no longer see his IDE drive in there. Or, rather, that is the only meaning I can see
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Monday 2006-03-06 at 00:07 +0100, Anders Johansson wrote:
He said:
] In Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list
Since USB isn't IDE, and therefore USB drives don't show up in an IDE list, he must mean he can no longer see his IDE drive in there. Or, rather, that is the only meaning I can see
You are picking a sentence out of context. The complete paragraph is: ] Now, I tried an external DVD reader on USB port and, suddenly, I can't ] read the DVD's with a reasonable speed anymore. In ] Yast/Materials/DMA-IDE setup I don't see the DVD reader in the list. So I insist to understand he is referring to DMA on USB drives; there are two references to "DVD reader" in the paragraph. I have to assume it is the same device he is referring to; and of course that external drive will not appear in Yast. Any way, it is absurd to continue this speculation: Alain has not written again since Saturday, and it is he who must speak up and clarify his meaning. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFEC40BtTMYHG2NR9URAmhbAJ9qZzXsXyr7uuJbOzn7gcclUcanEQCgksLW f5ZGh01g3og+4iSIRaAusTo= =Q4Cu -----END PGP SIGNATURE-----
participants (4)
-
Alain Barthélemy -
Anders Johansson -
Carlos E. R. -
Randall R Schulz