[solved ] incorrect 'power on' hours value on X25-M when DIMP enabled

[KMora3]

Hi there,

For a long time already, I've been noticing Intel SSD X25-M 120 GB (and possibly also 320) has got incorrect 'power on' count hours in S.M.A.R.T. report. I'm running my Montevina based ThinkPads (one X25-M, the second with 320) for many hours each day, yet the count kept suspiciously low.

The other day I had spare time and run following experiment:

-took a note about power on count at morning and let my machine run for all day and night long (no sleep/hibernation mode)

-took a note again next morning

I've done this twice and records are following:

-first morning: 1144 hours

-second morning: 1144 hours-third morning: 1145 hours

(see attached screenshots)

Obviously 1 of its "hour" is longer than regular day.

reporting tools: SSD Toolbox and CrystalDisk Info

According to your information (see https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18455 https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18455 ), my drive has got latest firmware.

Thank you,

Karel

[Kei_K_Intel]

hey kmoravec,

Interesting observations you've got there. Seeing that you are running on a laptop, I suspect there are other power saving modes which exist within the laptop that you may not have disabled. Have you checked Link Power Management (LPM) features such as HIPM or DIPM? My initial hypothesis is that the drive is entering some sort of power saving mode where the internal SSD controller stops counting clock cycles. Do you simply run the system idle? Perhaps running a continuous workload to ensure the drive stays "awake" would be the best method to test this. (Albeit at the cost of the longevity of your SSD)

or maybe you did find something wrong with the power on counter

-Psignosys

[KMora3]

Hi Psignosys,

Let's see what Intel has got to say about it.

I didn't think of this at first, but even if the drive goes to power saving mode it isn't completely powered off and should be aware of current time. Also, I didn't observe this problem on SSD 510 (though it's got different error reported /message/196306# 196306 here), it reports power on hours correctly.

Cheers,

k.

[Jose_H_Intel1 · Accepted solution]

Thank you for posting.

DIPM is indeed related to Power-On Hours Count:

"The raw value reports the cumulative number of power-on hours over the life of the device.

The On/Off status of the Device Initiated Power Management (DIPM) feature will affect the number of hours reported.

• If DIPM is turned on, the recorded value for power-on hours does not include the time that the device is in a "slumber" state.
• If DIPM is turned off, the recorded value for power-on hours should match the clock time, as all three device states are counted: active, idle and slumber."

[KMora3]

Hello Joe,

Thank you for pointing this out! I was aware of DIPS (every now and then I see on AnandTech people complaining that they don't enable DIPS when testing SSDs on power consumption), but didn't realize it's enabled by default. With DIPS disabled, 'power on hours' keep adding up normally indeed.

Enabled by default on mobile platform, that is (confirmed on Montevina and Calpella platforms). DIPS is disabled by default on desktop machine (at least on Denlow platform). I also noticed when SSD connected via SATA-to-USB bridge, DIPM wouldn't trigger even if it's enabled by operating system (possible feature/bug on my external drive IC).

I don't have my old machine with X25-M available anymore so I've confirmed your info on Denlow platform and Intel 320 model.

How to check DIPS status

Run Intel SSD Toolbox, Drive Summary, Drive Details:

word 79 (Serial ATA Features Enabled), bit 03 (Device Initiated Power Management Enabled😞 0 (disabled) or 1 (enabled)

How to control DIPS mode in Windows

It is possible to control DIMP (and HIMP) in power control section with following two entries in registry:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\0012ee47-9041-4b5d-9b77-535fba8b1442\0b2d69d7-a2a1-449c-9680-f91c70521c60]

"Attributes"=dword:00000002

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\0012ee47-9041-4b5d-9b77-535fba8b1442\dab60367-53fe-4fbc-825e-521d069d2456]

"Attributes"=dword:00000002

New item would appear in 'hard disk' section which allows to control DIMP:

AHCI Link Power Management with options: Active, HIMP, HIMP + DIMP

Thanks,Karel