Need some RAM benchkmark knowledge

[zKorsakov]

Im having trouble with a notebook Acer Aspire 515-51-52TE which cant boot windows, idk why, the screen stays black, and i can only move the cursor. But nothing else happens. Anyways, i was doing some memtest and disk test, no errors at all, but i made this memory speed and its lower than other benchmarks i saw... so my question is: Is this normal? What can cause it?
Also, if someone has any knowledge about non-booting computer problems, this notebook had a clean windows install 2 days ago(Had to wipe because of the non-booting windows black screen problem), and it was working just fine, but now again same problem.
Oh and i made a memtest with sequential cores, and round robin, both tests froze.

[zKorsakov]

Ok so, i ran a few more tests, and now it has a very different speed

[David (PassMark)]

I don't think the benchmark speed is the problem. Slow RAM doesn't generally prevent a machine from booting.

I made a memtest with sequential cores, and round robin, both tests froze

So MemTest86 worked OK in single threaded mode and successfully did 4 passes?
How long did the freeze take to occur in the other modes?

Can you CTRL-ALT-DEL to get to task manager when you see the black screen?

[zKorsakov]

It worked ok in Parallel, 4 passes 0 errors, didnt try in single core, dont know really which core to test... No, i cant get to the task manager, it passes Acer logo, and then the screen will stay black , sometimes there's cursor, sometimes there's not. Also, there were 2 attemps to boot windows, and i could get to the user login, and everything was black except for the buttons and the password field.
Edit: i was making a new ram speed test and the pc froze
Edit2: Round robin froze at 01:24 (1min 24 secs), in test 6, and sequential core froze at 02 secs from the start, in test 2

[David (PassMark)]

Edit2: Round robin froze at 01:24 (1min 24 secs), in test 6, and sequential core froze at 02 secs from the start, in test 2

It might be possible to explain this as a BIOS bug (if there was no other symptoms).

Edit: i was making a new ram speed test and the pc froze

It is hard to imagine how this could be anything but a hardware failure.

Is the machine under warranty?

[zKorsakov]

Is the machine under warranty?

Unfortunately not, but ill send it to a technician, this is too far my knowledge, i really appreciate your help.