Dark's Code Dump

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Adventures with LTO Tape for Home/Casual Use

I’ve spent the past while buying and experimenting with some old LTO gear as a secondary backup solution besides backing up to both local disks and cloud. I chose LTO because:

  • My upload speed is trash so the only way I can hope to do a full off-site backup is via physical media
  • With LTO4, it works out cheaper than buying about 2-3x 2+TB external hard disks, especially if you go SCSI instead of SAS.
  • I have the option of taking tapes out of rotation and storing them long-term. With hard disks this is risky and expensive.
  • Good for air hand luggage
  • It’s old school cool

My learnings and notes follow…

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VW Composition Media M3U playlist bug

Spent the best part of 2 days trying to figure out why the composition media system (same probably applies for discovery media system) in a MK7.0 VW Golf was failing to read M3U playlists, with the error “No playable files found”.

Tried every combination imaginable of file paths, separators, line endings, and even went as far as writing a script to generate extended m3u data from a plain m3u, but nothing made any difference.

The fix turned out to be very simple: have more than one folder on the SD card with MP3 files in it. The software must have a special case for all MP3 files in one folder that (probably unintentionally) breaks playlists. Even a single mp3 file in a second folder is enough to kick it into life.

Once this fix is in place the M3U support is pretty comprehensive – plain or extended and a variety of line endings and path separators all work fine.

Fix for Gigabyte motherboard boot loop on resume from sleep

From what I’ve read, this seems to affect a large percentage of Gigabyte motherboards since S3 sleep became a ‘thing’.

The issue is as follows: on a significantly overclocked Gigabyte motherboard (high end or low end), when resuming from S3 sleep the screen never wakes up and after about 15-20 seconds, the system repeatedly turns off and on again every few seconds. The only way to break this loop is to completely remove power from the PSU for several seconds.

The issue is connected with PCIe power, as evidenced by the various reported fixes of disabling onboard NIC power saving and reverting from Intel/AMD AHCI drivers to the Microsoft default ones.

The real fix is very simple: Use Balanced power mode in windows and check that PCI Express Link State Power Management is set to ‘Moderate Power Savings’ and not ‘Off’. The fact that the default setting of moderate does not have the issue explains why it is not more widely reported.

Fix for Samsung 750 and 950 series monitors 120Hz “Not Optimum Mode”

2018 Update: The below advice applies to non-standard resolutions (i.e. anything but 120hz 1080p), which can drop to Not Optimum Mode after 60 seconds consistently. This is not the same as the roughly once per few days Not Optimum Mode which is a fact of life with these monitors.

Use 120.8Hz custom refresh rate. Both Windows and the monitor’s OSD will show 121Hz. Actual 121.0Hz will cause the error without fail, it must be a tiny bit below. I guess there is something weird going on with the tolerances in the monitor – I’ve noticed things like mains current spikes contribute to the problem.

This may apply more to HDMI 1440×1080 or 1280×720 than to DisplayPort 1080p.

My exact settings for 1440x1080x120Hz over HDMI are as follows: