Page 1 of 1

my HDDs or Vista gone insane fast (scary)?!

Posted: Mon Sep 29, 2008 6:18 pm
by Marin85
Hi,
In my ThinkPad I have a 200 GB Hitachi 7K200 as a main hard drive and a Toshiba 120 GB 5400 rpm (don´t remember the exact model) in the ultrabay. I have been recently observing unusually high transfer speeds from the Hitachi drive to the Toshiba drive when copying files in the range from 200 MB to 4 GB (archives, isos and the like). And by high speeds I mean transfer rates over 100 MB/s, often about 200+ MB/s and dropping to 150 MB/s. Interestingly, the transfer really processes fast, so I don´t believe it is some kind of Vista bug showing wrong transfer speeds (I recently moved out an iso image of Fedore about 3.5 GB that started at about 250 MB/s and copied over just for few seconds!). I checked the size and the integrity (md5, sha1) of these files and it´s all correct. What is more, I don´t receive any errors of any kind when using these files.
Here two desktop screenshots of copying an XP-iso (with SP3 slipstreamed):
http://img184.imageshack.us/my.php?imag ... nceni1.jpg
http://img90.imageshack.us/my.php?image ... ce2ag4.jpg
It could be some new feature of Vista arrived among the other updates :P (which is quite improbable) or there is some weird problem with one of the drives. I haven´t run any check on them, the HD Tach and HDtune benchmarks are normal. For the record, this only happens when copying from the Hitachi drive to the Toshiba one, the other direction runs normal.

Any comments?

Marin

EDIT: @Mods: I have a kind request to move out this thread to the general hardware and software section if possiobe as I have just realized that I have posted in the wrong subforum. Thanks in advance! :)

Posted: Tue Sep 30, 2008 1:11 pm
by Marin85
Anyone? :) I´m really a bit of scared because of this and I hope my drives won´t fail me some day when I really need them due to "overperformance" :?

Marin

Posted: Tue Sep 30, 2008 1:54 pm
by aaa
I'm sure they're not actually going that fast, that would be impossible. I think it has something to do with Vista's cache.

Posted: Tue Sep 30, 2008 5:15 pm
by Marin85
that would be impossible
Precisely, that was the scary part (Nothing is impossible, though :lol:). I also think it has something to do with the way Vista caches files. My observation is that this happens mostly to big files (like big .iso images, .rar archives etc) that have been manipulated in some way before. So, it´s actually quite intelligent of Vista to cache them in order to possibly process them much faster next time including copying and similar. However, I have no explanation for the fact that after the very few seconds of copying the file onto the other physical drive a hash check can be completed successfully, whereas a "normal" copying would take much longer than "fast" copying + hash calculation, unless a hash check runs so to say only virtually in Vista, or alternatively, it checks only the cache but not the actual physical copy. The latter would mean less reliability of Vista´s copying engine :?
I now remember about a guy explaining that due to the great amount of complaints about slow copying in Vista M$ has removed some check feature from the copying algorithm to speed it up.
Anyway, I hope it´s nothing serious.
Thanks for your reply, aaa!

Cheers

Marin