20A3P vs. 20A4P Jitter

I crossflashed an Optiarc AD-7190A to a Litey DH-20A3P last night, and did some quality scans with it at different speeds using the same disc. I also scanned the same disc with a 20A4P @ 4x and (just for kicks) a DH-16D3P @ 2x. The scans for the 16D3P, 20A4P, and 20A3P @ 2x look very similar. The 20A3P scans at higher speeds degrade. What troubles me is the jitter results for the 20A4P (very good) vs. the 20A3P (not so good). Are other folks seeing the same thing? Here's the scans:

There is a register hack to seting the jitter speed regardless the scan speed selected. http://club.cdfreaks.com/f44/jitter-...ed-new-228166/

Thanks! I'll certainly use the registry hack to force jitter scanning to 4x. However, since I assume the default is to do jitter scans at the scan speed selected, and I'm seeing much higher jitter on the 20A3P than the 20A4P at all three scan speeds, I'm puzzled as to which drive to believe the jitter results from. Which is the more reliable drive for jitter scanning?

My 20A3P always show much higher jitter than my other drives when scanning at 8x.

The way the drives scan jitter is different. I can't quite explain it, but much like in zhadoom's case, scanning with an A3 will have higher (or at least vastly different) jitter on some discs in comparison to an A1/A4's jitter scan.

I think the A3 scans more like the later iHAS drives, but I haven't actually paid that close attention.

@ zhadoom and Albert:

Thanks for the feedback and your insights.

@ Albert:

I think you're right about the 20A3P's jitter results being high like the iHAS drives. I'll try some test burns this weekend and compare jitter results for the 20A3P, 20A4P, and iHAS422 to verify. Unless someone else already has?

I ran into a problem with the 20A3P - it was reporting extremely high PIEs for MKM 001 media, while the 20A4P and iHAS422 did not. So I switched to an external DX-20A3P (f/w YP5W), but CDSpeed and Opti Drive Control will not report jitter for that drive. Any ideas on how to get jitter working for that drive?

Correction to my previous note: the external drive is a DX-20A3H. I've tried it on two different computers, and neither CDSpeed nor Opti Drive Control 1.43 will scan jitter. Both stop right after the quality scan, with no error message. Could it be that CDSpeed and ODC do not recognize the DX-20A3H as a Lite On drive capable of scanning jitter? Or do i need different firmware for the drive?

All of the following it hypothetical...

Did you ensure that you can actually enable jitter (not the display of jitter, but the scan for jitter) for the DX-20A3H in CD Speed? (While in the Disc Quality Scan tab, click on "advanced" and see if you can change the option to scan for jitter).

Maybe ODC has to be "set" in a similar way; I do not know.

It's also a possibility that the USB (I presume) enclosure just generically responds to the command to scan for jitter with something that won't trigger an error message with either of the scanning utilities.

Doesn't the drive just report itself as a D[H]-20A3H to everything? I the A3P worked, the A3H should be on the same whitelist to work.

I think that drive was able to scan jitter with all versions, but I cannot say for sure.

Thanks, Albert. Yes, jitter scanning is enabled. I can scan for jitter with a DH-20A3P in a generic external enclosure (with both CDSpeed and ODC), just not with the 20A3H in the Lite On external enclosure. The DX-20A3H does indeed report itself as a "DH20A3H USB device". Perhaps it is the Lite On enclosure?

It's quite possible that the LiteOn enclosure is to blame. I know I can scan for jitter with my EZ-DUB DX-20A4P (LiteOn enclosure; reports itself as a DH20A4P), but maybe it doesn't work perfectly with the 20A3H. If you have nothing to lose, try swapping the 20A3H and the 20A3P to see if the A3P will at least try to report jitter in the LiteOn enclosure, or if the A3H still fails in the alternate enclosure.

Thanks for the suggestion, Albert. I may have to resort to that. But in the meantime I tried out an external 20A4H which is in a Lite-On external enclosure identical to that of the 20A3H, and it reported jitter just fine. The date on the 20A4H enclosure is January 2008, and on the 20A3H enclosure is September 2007. I think I have another external 20A3H somewhere around here, so I will try that out also.

I couldn't find another external 20A3H, so I removed the one I have from the Lite-On enclosure it came in and transferred it into my generic external enclosure. [This is the same enclosure in which a 20A3P and a 20A4H reported jitter just fine.] The 20A3H still will not report jitter. With CDSpeed I get an "Error! Invalid field in CDB (052400)", and with ODC it stops after the quality scan with no jitter attempted. I believe this points to either CDSpeed and ODC not properly recognizing the drive as capable of scanning jitter, or the need for different firmware.

More than likely. I say, "go flash happy". Try the various firmwares found floating around the forum for the drive, including the "test" firmware (for the DH20A3 series drives) from LiteOn many people use in the stead of the stock firmware. Also, there is the enhanced firmware from C0deKing that provides better writing quality. He typically uses the latest, most feature rich firmware for his projects.

Thank you, Albert. I will follow up on testing out CodeKing's enhanced firmwares. In the meantime, I discovered that one of my external enclosures is acting weird, such that when any drive is in it the drive reports very high PIEs, PIFs, and jitter. I'm not sure why, but it's definitely strange. So I was able to do jitter scans of a set of three discs using several drives (avoiding the bad external enclosure) to see how the jitter results compared. Probably this has already been done, but I wanted to verify on my drives. I'll post separately in this same forum. Thanks for all your help.