rMBP write speeds slow down?

[Mr.Skynet]

I just did a fresh install of OS X Yosemite and after I installed all my apps, my write speeds have dropped to 342 MB/s when the computer should be putting out about 712 MB/s. What the hell happened? This computer isn't even a year old yet and it slows down this much? Any suggestions?

 

[Samuelsan2001]

Have you loaded back some data?

If you have loaded back a lot of data it could be spotlight indexing this will interfere with blackmagic speed test.

 

[Weaselboy]

I just did a fresh install of OS X Yosemite and after I installed all my apps, my write speeds have dropped to 342 MB/s when the computer should be putting out about 712 MB/s. What the hell happened? This computer isn't even a year old yet and it slows down this much? Any suggestions?

Do a command-s boot to single user mode then enter "fdisk -fy" (without the quotes) at the command prompt. That will TRIM all unused blocks on the SSD and hopefully get your write speeds back to like new.

 

[Mr.Skynet]

If you have loaded back a lot of data it could be spotlight indexing this will interfere with blackmagic speed test.

That might have contributed, however I noticed that I enabled the FileVault encryption when I reinstalled and that was killing it! Disabled and now its back to normal. Thanks for replies guys!

 

[Weaselboy]

That might have contributed, however I noticed that I enabled the FileVault encryption when I reinstalled and that was killing it! Disabled and now its back to normal. Thanks for replies guys!

FV does slow it a bit, but should not by the one half you are reporting. So you did a speed test before and after FV and it went from 712 to 342 write speeds?

 

[cjmillsnun]

I have FV enabled and get this...

I suspect your issue is more down to something else.

 

[Mr.Skynet]

I have FV enabled and get this...

I suspect your issue is more down to something else.

It's not that its slowing them down. When I did the speed test and got the low write speeds, it was because it was currently encrypting the drive while I performed the test. As soon as I finished the encryption the speeds went back to normal.

 

[cjmillsnun]

It's not that its slowing them down. When I did the speed test and got the low write speeds, it was because it was currently encrypting the drive while I performed the test. As soon as I finished the encryption the speeds went back to normal.

That makes more sense. So in effect the disk was busy.

 

[Weaselboy]

It's not that its slowing them down. When I did the speed test and got the low write speeds, it was because it was currently encrypting the drive while I performed the test. As soon as I finished the encryption the speeds went back to normal.

Oh heck yeah... that would kill a speed test.

So speeds are back to normal now?

Glad you are fixed up. FV encryption is a really great feature and the first thing I do on any new Mac.