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LG GSA-H22N and UDMA 4

PostPosted: Sun Jan 21, 2007 3:38 pm
by 2Dogs
I just re-read one of Ian's H22N threads, and realised that all my tests on my LG have been with it set to UDMA 2! :oops:

I therefore set DMA mode select to "auto" in bios, and sure enough, the LG is picked up as UDMA 4, and shows that in device manager.

When I re-ran a CD-DVD Speed TRT on a +R disc, however, the LG is reading really slowly. The burst rate has gone up from 20MB/s in UDMA 2 to 29MB/s in UDMA 4, but the maximum read speed has dropped from about 16x to 8x, with a corressponding drop in the initial read speed too. Here's the TRT image:


My LG is set to slave on the middle of my IDE cable, with my old KHypermedia set to master at the end of the cable. I tried the TRT test again with both burners set to cable select, just to cover more bases, but with the same result.

Any ideas what's causing this? I'm using TDB region free 1.01 firmware.

PostPosted: Sun Jan 21, 2007 4:32 pm
by 2Dogs
Maybe it's a glitch in the TDB 1.01 firmware. I was able to use MCSE to remove the riplock, and TRT results were restored to their former speeds.

I then wondered if there would be any changes to the write quality when operating under UDMA 4. Here's a test burn at 16x to Memorex 16x DVD+R (CMC MAG M01) made in Taiwan media:


Here's a test burn I did previously with UDMA 2 enabled. (it's not the same project, but a similar 4463MB one)


So using UDMA 4 seems to have reduced PI errors by about 50%, whilst the overall quality score is reduced to 96. Not really too much difference, considering the range of variation in CD-DVD Speed tests. I don't fall into the trap of believing my scans to be absolute measures of the disc quality - I would love to be able to compare the results I get using my BenQ 800 clone as a scanner with a DW1640, for example - but at least I believe I can realistically compare burns to different media.

I suppose I should re-run the burn without the riplock patch, just in case that's having some effect on write quality.

PostPosted: Sun Jan 21, 2007 5:03 pm
by 2Dogs
Well, running the disc quality scan again for the same disc without the riplock patched 1.01 firware gave a similar result. Although PI errors and failures are up, and the quality score has dropped a point, it may well be within the range of variation in the test, so it's inconclusive. But maybe it shows that the riplock patch isn't adversely affecting the writing quality - a good thing.


PostPosted: Sun Jan 21, 2007 5:33 pm
by n4rk0

i have the same lg unit i dun know about udma modes or that kind of things if u can explain to me whats the different udma 2 or udma 4 i really dunno wtf is that if u can help me ill appreciate it

PostPosted: Sun Jan 21, 2007 6:28 pm
by 2Dogs
Hi n4rko,

your scan looks pretty similar to one I did with my LG with UDMA 2 - especially the burst rate, which shows as 20MB/s.

I'm still trying to figure out if running at UDMA 4 improves anything - and specifically writing quality. There doesn't seem to be much difference with the Memorex 16x DVD+R discs I've burned with, but I'm going to retest some RICOHJPN R03 media that my LG definitely didn't seem to like burning to with UDMA 2.

UDMA 4 is supposed to allow faster burst rates for one thing, and the transfer rate tests seem to confirm this - but like I said, I'm not sure if I'm seeing any great benefits from it. On the other hand, if my writing quality is not made worse, then there's at least no harm in it.

I'll assume you are running Windows XP, but it's similar for 2000. Excuse me if I'm teaching you to suck eggs with any of the following!

First off, you need to have a pc that can take advantage of the higher transfer rates, so an older motherboard might not support it. Secondly, you have to use 80 wire IDE cables to connect your drives. Most newer pc's would have these cables and would support UDMA 4 - so the easiest thing to do is first to check what you have in device manager, and click on "IDE/ATAPI controllers". If you have a pc, there will most likely be two controllers, but laptops commonly have just one. Right click on the "primary IDE channel" or "secondary IDE channel" and click on "properties". Then click on "Advanced Settings" and you will see the "Current Transfer Mode" for devices 0 and 1 on that channel. One of these will be your burner - typically on a pc the burner would be on the secondary channel, and if you only have one optical drive, it would be device 0.

Now if your pc does support UDMA 4 and you do have an 80 wire IDE cable connected to your burner, you can set it to UDMA 4 in bios. To do that, you'll have to hit one of the "F" keys when your pc is booting up. Which key it is will vary according to your pc, but on my HP, it's either the F10 key, which gives me a simplified menu of bios options, or the F11 key, which gives me more options.

Having identified where your burner is - say device 0 on the secondary IDE channel, you can set the DMA select mode in bios to "Auto". Then when you boot up, the LG should be picked up as a UDMA 4 device.

Whether or not that then gives you any real benefits, I'm not sure. I have noticed, however, that when I burn a disc with Nero 6, the "buffer state" seems to stay in the 87% to 94% range. Previously, running in UDMA 2 mode, the buffer state would fluctuate a lot more. It may or not have some effect on burning quality.