PlexTools Q-Check TA Test - What do results actually mean?

Hi all, I’ve been trying to do more testing of my burned discs…both newly burned and those I burned 18-months ago. One of the tests I started running last week is the Q-Check TA test, but I’m not too sure that I really understand what the results are telling me regarding, in particular, the prospect of long-term stability/durability of the disc contents which, afterall, is the ultimate goal for me.

I am pretty clear that you want test results where the peaks on the histogram are nice & narrow, and there is no peak shift or the peaks running together. So higher scores of 4 & 5 tell you that’s been achieved.

Does that translate into being one of the factors leading to better long-term performance of the disc, though?

Thanks so much for any guidance you can provide on the value of this test! :slight_smile:

(btw, my version of PlexTools is 2.17…which is what came with my PX-716A drive…can’t find any sort of update on the Plextor site)

Please check the excellent FAQ by G@M3FR3@K:
http://club.cdfreaks.com/showthread.php?t=49767

Instead of PlexTools Professional use PlexTools Professional LE 3.13. You’ll find it here:
www.plextools.com

Consult the included help file and ‘?’-Buttons of PlexTools; and of course the ‘Search’-function in this forum.

Hi Baiocchi, thanks for trying to help! :slight_smile:

Before posting my original message I DID indeed read the FAQ you referenced…I’ve just now taken several minutes more reading through it all again. I can find nothing there that answers my question…in fact, there is only a passing reference to the TA test contained in that FAQ; certainly no hints in understanding what the test results might indicate about the long-term viability of the disc’s contents. I’m not making a knock against the FAQ…on the contrary, it’s been quite helpful to me on other matters…no FAQ can cover everything! Maybe I’m just blind…if you can point me to a particular section where interpreting the TA test is covered I’d be very grateful!

Thanks for the suggestion about the free PlexTools Professional LE…I’ll take another look at that. I’d been seeing other forum members here posting scans using PlexTools Pro 2.35 and was looking for that update! :o But it looks like that version is history and LE might be a worthwhile upgrade of my version 2.17 of PTP.

Re: the search function of the forums…please believe that I did a search before posting…several searches in fact, using different phrase variations…and found nothing obvious that addressed my question. I’m not saying that somewhere buried inside some thread here there isn’t an answer already posted…but I read through many possible threads and couldn’t find anything; it seems to me that there is some limit after which you stop searching and you just ask the question…that’s what forums are for, afterall. If my question is a repeat of somebody else’s…my apologies. :flower:

The whole reason that I asked this question is I’m trying to decide if it is worth the time for me to go through a few hundred burned discs and perform the Q-Check TA test on each disc…sort of establishing a benchmark reading that I can put into my burn records. If the TA test results are REALLY going to help me manage/monitor my disc collection, I want to make that time investment now and run the tests. On the otherhand, if the TA results don’t really mean much regarding long-term stability/durabilty of the disc contents…well, it’s probably good to know that. :wink:

Thanks again, Baiocchi.

I believe this test shows the quality of the “pits and lands” in the CD/DVD track. The better defined these are, the easier it will be for a drive to read them and the better chance they have to stand the test of time. That said, there are many other factors to be taken into account with reference to longevity of CD/DVD discs. A badly made or stored disc could be deteriorating right before your eyes, even if it just gave you a perfect TA Test.

In addition, here’s my first Search hit :wink: : http://club.cdfreaks.com/showthread.php?t=142342

:o That’s pretty embarassing…

thanks for the link, Cressida…

and thanks for your assessment of the meaning of the test results[I]…"The better defined these[/I] [the pits & lands] [I]are, the easier it will be for a drive to read them and [B]the better chance they have to stand the test of time.[/B] [/I]

That’s what I wanted to know!

EDITED to add: btw, when I searched “Q-check TA Test” this link comes up at the end of page 2 of the results…and I never got that far after reading through all the other results listed…

searching “Q-Check TA” …end of page 3 :eek:

searching “PlexTools Q-Check TA” (the EXACT title of the thread!)…end of page 2 of the results! :confused:

I know, I know…a pretty weak defense! :rolleyes:

can’t figure out how you got it to be at the top of the results…I bow to you, Cressida! :bow: :clap:

A word of caution on the above:

The organic dye used to burn the pit/land structure into is a ‘unstable’ thing. It will decay over time. That is only natural. TA-Test will NOT give you any information about how [U]stable[/U] a dye is, whether its rate of decay is fast or slow, etc. TA-Test will only tell you how the pit/land-structure looks to the drive [U]at the moment of testing[/U].

Obviously a good structure has more chance to survive the coming decay than one that is bad to begin with. Due to the decay the bad structure may become unreadable much sooner than a good one. So TA-Test will allow you to see how much chance for ‘endurance’ a disc may have in the future. However, it will not tell you how long that endurance will last. One kind of dye may - for example - burn well initially but show a high decay-rate afterwards. Another may burn badly but stay most stable afterwards. So you can use TA-Test to determine the rate of decay only by doing consecutive scans over a period of time.

Actually, I used Google for this one… :wink:

:bigsmile:

Thanks so much for the extra information…this is all so very interesting…trying to understand as much as I can! :bow:

Just a bit more…I have some idle time. The TA, or Time Analysis, shows the grouping of the pits and lands that make up the encoding. Each 8 bit computer byte is translated into a 14 bit serial word for writing (Eight to Fourteen Modulation, or EFM). The bits in this code are not representing 1’s and 0’s, but are various lengths of burned (pits) and unburned (lands) dye in the prestamped groove. There are 11 data bits and 3 ‘frame’ or separator bits for each ‘word’. The duration and presence (or absence) of reflection is decoded during the read and translated back to the original 8 bit data. The lengths are fixed by the Red Book standard and are listed as T3 (shortest)-T11 (longest). The TA shows the quality of these T3-T11 burns. There are generally more T3 bits, so the tighter the grouping of these bits, as well as the other, the greater the conformity to the book standard, and the better the readability. If the TA results are muddy, the disc has got a strike against it before you even put it away.

As also mentioned above in the other posts, this tight grouping or 4/5 result does not mean diddly if the discs are not immediately stored properly in jewel cases or some such storage and kept in a stable temperature and humidity environment. If you start with good quality discs and store properly, they will last a long time.

:bow: TOTALLY awesome info, bob11879 !!! Many thanks for taking the time to explain this in more detail! :flower:

getting a little scary…I’m actually starting to understand this! :eek:

:cool: