On Monday, September 24, 2018 at 1:13:21 PM UTC+2, Brendan Hoar wrote: > On Saturday, September 22, 2018 at 12:06:04 PM UTC-4, Marcus Linsner wrote: > > Actually I have to correct the record here. Basically I was wrong about the > > cause of this 2MB/sec write speed being caused by that new Samsung firmware > > update: > > > > The fact is, I don't know when that rewriting/refreshing takes place(it > > could be even more often than I thought, if judging by the SSD temperature > > being usually 44-47 Celsius, and only sometimes 32-35 Celsius)! > > What I was seeing as 2MB/sec was in fact a quirk of my Lenovo Ideapad Z575 > > laptop whereby after one(and any subsequent) Windows 7 Restart (ie. > > Start->Restart) the random write speed would be capped(I don't know why) to > > that 2MB/sec and only a Sleep or Shutdown would bring it back to normal! > > And this only happens when the SSD is connected via a drive caddy in place > > of the optical disk drive(ODD), alone with nothing else connected (on > > ESATA, or main drive bay). >
> That seems to point to the bios (re-?)initializing the drive into PIO (polled > IO) mode instead of DMA mode. Does the BIOS have the sata ports set to AHCI > mode? Is the BIOS up to date? Is the drive tray from a 3rd party, not Lenovo? I've come to the conclusion that's not the BIOS itself(at least no alone), because the issue happens only after a Restart from within Windows 7 (or Linux) (so not a restart from BIOS eg. after a Save&Exit, or even after just a ctrl+alt+del at the bios or poweron password dialog). Furthermore, if I place only a Kingston (240G) SSD on ESATA port (with nothing else SATA connected, eg. on main drive bay OR optical drive bay) then it works fine until the first win7 Restart which then brings the random write speed down to 2.7MB/sec (around 670 IOPS). In BIOS mode is set to AHCI (instead of IDE). Now, if I do place a Samsung (840EVO 1TB) SSD on the ESATA port, no matter how many restarts, the speed slowdown doesn't happen! But if I place the Samsung on ODD bay (non-lenovo drive caddy), then after a win7 Restart, I experience the slowdown. But not if I place a Kingston SSD on ODD! I don't know, it's weird! BIOS is as up to date as they've released it (2011) https://pcsupport.lenovo.com/us/en/products/LAPTOPS-AND-NETBOOKS/IDEAPAD-Z-SERIES-LAPTOPS/IDEAPAD-Z575/downloads/DS027070 Keeping track of the issue here: https://gist.github.com/constantoverride/7fc7974eb0d5dd48f4ebe5bc84e623f3#gistcomment-2713815 Though I've stopped testing stuff for now, until (if ever) I get some better ideas. Thanks for all the info, Brandan! Appreciate it. -- You received this message because you are subscribed to the Google Groups "qubes-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-devel/ea8b9e29-f5b0-49c9-842b-260f86861104%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
