PIO mode

[Dave48838]

How do I check if a drive is in PIO mode? I've got a laptop and the read/write time is taking forever. What free or inexpensive software would I be looking for? How do you put a drive in and out of PIO mode?

[Vulcan]

How do I check if a drive is in PIO mode?

Which OS?

Windows - Use "Device Manager" (a Google search for Windows PIO mode will give lots of sites explaining more).
Linux - hdparm is your friend.

I've got a laptop and the read/write time is taking forever.

This is often a symptom of another problem, and therefore even if PIO mode is being used, just switching it back to UDMA is not a fix, because you wouldn't be resolving the root cause.

[Dave48838]

The OS on the customers drive is a bootleg of win7 ultimate his son had put on, originally vista. The OS I'm using is either xp or 7.

What are some "root cause"s of a drive going into PIO mode?

I read on http://seagate.custkb.com <-- a google search, that "XP will turn off DMA mode for a device after encountering certain errors during data transfer operations". What kind of errors? time outs, delays in read/writes. I'm assuming if XP can turn off DMA, any OS can turn off DMA.

What tests can/should I run on this drive to figure out the underlying cause(s) or should I not even bother and get him a replacement drive?

[pcimage]

I would run the relevent drive diagnostics and health check on the drive, as like Vulcan says there is almost certainly an underlying problem (bad/weak sectors for example).

Or better still, just replace the drive

[fzabkar]

Windows XP will downgrade a drive's performance from DMA mode to PIO mode if it detects more than 6 CRC errors.

DMA Mode for ATA/ATAPI Devices in Windows XP:
http://www.microsoft.com/whdc/device/st ... E-DMA.mspx

DMA reverts to PIO:
http://winhlp.com/node/10

Check the SMART report.

If a drive is running in PIO mode, then a HD Tune read benchmark graph will be a flat line.

[Vulcan]

@fzabkar,

Hi - That's exactly the info that I was leading the OP to find (teach a man to fish etc. ), although we don't yet know if his guess of PIO mode is the reason for the reported poor performance. As I explained to him (and as your links kindly confirm), entering PIO mode is typically the result of a problem elsewhere...

@Dave48838,

I'm assuming if XP can turn off DMA, any OS can turn off DMA.

Yes that's theoretically true, but this information is IMHO totally useless in your situation as it does not tell you (a) whether PIO mode is even being used on your customer's system and hence whether this could explain the symptom of poor performance (you could be looking in totally the wrong area!); (b) whether any other OS chooses to have that behaviour.

Rather than asking theoretical questions, can I suggest that you check Device Manager for the current transfer mode being used by that drive, when its in the "problem" state, and let's see if PIO even applies in this case?

What tests can/should I run on this drive to figure out the underlying cause(s) or should I not even bother and get him a replacement drive?

The cause of this slow performance might not be the drive - so as pcimage said, further diagnosis would avoid you feeling silly by getting a replacement drive, and having the same result.

Diagnosis can be an iterative process, so don't expect an exhaustive list of everything to do, especially without having supplied any data - I'd start with what fzabkar kindly suggested: Gather the full SMART data (inc raw values) and HD Tune Pro (or equivalent) read benchmark graph for the whole drive, review the results, and if you're not sure what they show, then supply them here and ask for opinions. I'd also suggest you look at the Windows System Event Log for entries related to the disk or disk interface. Also you'll need to explain the config you used to collect any data that you supply (i.e. Using your PC or customer's PC? Drive attached via (S)ATA, or USB-(S)ATA enclosure or ...?).

If you need further help, please give the drive model, what the originally reported problem was from your customer, and what happened shortly before their reported "problem" started (drive/laptop was dropped or knocked?) or whether there has been a slow degradation of performance or whatever. I'm not guaranteeing that I'll have time to reply, but the more (useful, clear & detailed) info you supply, the greater the chance of you getting help IMHO.

[Dave48838]

More info as requested by Vulcan is now irrelevant, I figured it out and as Vulcan said, I may be looking in the wrong area. I had more time to work on it today. I ran a couple tests with hd tune and everything is looked fine (like a brand new drive), I ran a mhdd scan and everything is looked fine, so I tried reinstalling windows again and it was still slow. Doing the same thing over and over and expecting different results, that's Einstein's (1879 to 1955 Einstein) definition of insanity. I had also previously ran a memory test so I knew that was fine as well.

I'm thinking where could my bottle neck be because this is a fairly new (six months) $1600 laptop? I removed the DVD-RW/CD-RW drive and threw in a old DVD drive I had laying around my shop, it didn't fit right but everything is smoking right along now.

I do feel kinda dumb, I'm guessing that there are some finger prints or something on the lens of the original optical drive (it is a super quiet running optical drive, I didn't hear the optics running back and fourth or anything like I hear on my personal laptop with a fingerprint or something on the disk). I was also basing the result on the install process as to how the computer would end up working. I have had past experiences like that.

Why I pointed to the HD right away, I don't know, probably because I didn't hear the DVD chugging and I've been getting in so many computers with bad drives I just presumed that it was the drive. I will work on getting a better diagnosis before I post on here next time.

Thanks everybody for your help,
Dave (tail between my legs and my head hung low)

[Vulcan]

More info as requested by Vulcan is now irrelevant

Oh great, so I (and others) wasted time replying to your request for help.

I tried reinstalling windows again and it was still slow.

It's not really clear to me whether the "slowness" was only during (not after) the installation of Windows - nor how this new info relates to the situation where you initially reported slow disk I/O, since you didn't mention doing any OS installation originally... As you say, it's not important now. :shrug:

I will work on getting a better diagnosis before I post on here next time.

Thanks - since you're working as a business and are asking for our help, yet you're getting paid by your customers and we're not, then not wasting our time doesn't seem too much to ask IMHO.