Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
My write speed varies all over the place and the arrow moves up and down erratically?

Is this an issue with the SSD?

Mine seems to get 500MB write and 700MB read but sometimes it only gets half of that for each one and the spedomitar seems to be very erratic and it jumps up and down.

It seems to be that only the write speeds are very erratic and they jump up and down during the speed test.
 
Last edited:

Alekto

macrumors regular
Nov 15, 2012
107
2
Tokyo
The test just does that. Eventually it'll settle on a final number.

That's all you have to worry about.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
The test just does that. Eventually it'll settle on a final number.

That's all you have to worry about.

Okay but my write speeds them to be very erratic: it'll go to 500mb in same test but then slow down to 400 or even 300.

The speedometer sometimes goes up and down erratically whereas the read speeds are always smooth and consistent.
 

Alekto

macrumors regular
Nov 15, 2012
107
2
Tokyo
When you say it's erratic do you mean it's giving you different figures at the end of each test or do you mean it's giving you different figures while it's actually running? If it's the latter, that's normal behaviour.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
When you say it's erratic do you mean it's giving you different figures at the end of each test or do you mean it's giving you different figures while it's actually running? If it's the latter, that's normal behaviour.

Different figures while running. It'll go to 500mb but then slow down to 400. Or it'll go to 400 and slow down to 300 during the write speed test (same test).
 

Alekto

macrumors regular
Nov 15, 2012
107
2
Tokyo
Different figures while running. It'll go to 500mb but then slow down to 400. Or it'll go to 400 and slow down to 300 during the write speed test (same test).

OK then its normal behaviour and nothing to worry about. As I said, the only thing to concern yourself with is the final number.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
OK then its normal behaviour and nothing to worry about. As I said, the only thing to concern yourself with is the final number.

My final number is different each time though? Sometimes I get 500 write sometimes 300.

The write meter jumps up and down and is not smooth in going up like the read is.
 

Alekto

macrumors regular
Nov 15, 2012
107
2
Tokyo
My final number is different each time though? Sometimes I get 500 write sometimes 300.

The write meter jumps up and down and is not smooth in going up like the read is.

Then I'm stumped mate. Sorry, maybe someone else has a better explanation than me.
 

hans1972

macrumors 68040
Apr 5, 2010
3,329
2,899
My write speed varies all over the place and the arrow moves up and down erratically?

Is this an issue with the SSD?

Mine seems to get 500MB write and 700MB read but sometimes it only gets half of that for each one and the spedomitar seems to be very erratic and it jumps up and down.

It seems to be that only the write speeds are very erratic and they jump up and down during the speed test.

Also you should look at random reads and random writes. Normal workloads on a computer is much more random than they are sequential.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
Also you should look at random reads and random writes. Normal workloads on a computer is much more random than they are sequential.

Does this point to my SSD being defective?

The write tests just seem inconsistent and the speed randomly drops and goes higher erratically.
 

legioxi

macrumors 6502a
Mar 2, 2013
644
76
Does this point to my SSD being defective?

The write tests just seem inconsistent and the speed randomly drops and goes higher erratically.

Unless you're experiencing an actual issue with your laptop, no.
 

Freyqq

macrumors 601
Dec 13, 2004
4,038
181
Does this point to my SSD being defective?

The write tests just seem inconsistent and the speed randomly drops and goes higher erratically.

That's just how that test is designed. It's the test, not the SSD. Most tests do the test in the background and give you the final score at the end.
 

BrandonPrice31

macrumors member
Dec 16, 2014
88
0
That's just how that test is designed. It's the test, not the SSD. Most tests do the test in the background and give you the final score at the end.


No but the speedometer will go to 500 and just drop down to 300 or 400 in the same test. I'm not talking about scoring 500 then next test scoring 400.

Is what I described still normal?

----------

That's just how that test is designed. It's the test, not the SSD. Most tests do the test in the background and give you the final score at the end.


I've watched videos of people using the same test online and theirs don't do that?
 

Freyqq

macrumors 601
Dec 13, 2004
4,038
181
No but the speedometer will go to 500 and just drop down to 300 or 400 in the same test. I'm not talking about scoring 500 then next test scoring 400.

Is what I described still normal?

----------




I've watched videos of people using the same test online and theirs don't do that?

The final score is the only one that matters. Also, the test is best done with nothing else open and no background tasks whatsoever. Any task going on other than the test affects the test score. This could even be spotlight indexing, which you can't even know is occurring otherwise.

Anyway, that particular test is just designed just to give you an idea what your SSD speed is for their particular brand of products. The one the SSD manufacturers use is ATTO and they run it on a PC with nothing installed.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
The final score is the only one that matters. Also, the test is best done with nothing else open and no background tasks whatsoever. Any task going on other than the test affects the test score. This could even be spotlight indexing, which you can't even know is occurring otherwise.

Anyway, that particular test is just designed just to give you an idea what your SSD speed is for their particular brand of products. The one the SSD manufacturers use is ATTO and they run it in safe mode on a PC with nothing installed.

I have nothing running in background.

My worry is that the write speed (in the SAME on-going test) will reach 450 write but then just drop to 300 and end up at 350. Their are times I've hit 475 end result but the whole thing for write is erratic. I'm going to do a video for you guys so you can tell me.
 

Freyqq

macrumors 601
Dec 13, 2004
4,038
181
I have nothing running in background.

My worry is that the write speed (in the SAME on-going test) will reach 450 write but then just drop to 300 and end up at 350. Their are times I've hit 475 end result but the whole thing for write is erratic. I'm going to do a video for you guys so you can tell me.

Every time you run it, you do 5 GB of writes. Eventually, it is going to slow down until TRIM and garbage collection clean the drive in the background. That test is suppose to be run very occasionally lol. If you were running it on a completely clean drive and ran 3 runs of the test from a boot drive that only ran that one test, maybe you'd get closely consistent results. Your drive is fine.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
I posted videos using Taptalk on my phone with other account.

See how the write speeds go up and fall and are all over the place? My reads don't do that.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
Every time you run it, you do 5 GB of writes. Eventually, it is going to slow down until TRIM and garbage collection clean the drive in the background. That test is suppose to be run very occasionally lol. If you were running it on a completely clean drive and ran 3 runs of the test from a boot drive that only ran that one test, maybe you'd get closely consistent results. Your drive is fine.

It's being doing this since the first test.

Watch the video - that's fine?

It ran like this on my first test I did with the program. Keep in mind this laptop is brand new. Why don't the review videos do that?
 

Freyqq

macrumors 601
Dec 13, 2004
4,038
181
It's being doing this since the first test.

Watch the video - that's fine?

Well, mine does it too. It's fine. I've had this thing since October 2013, and the SSD has been fine this whole time. If you want the professional level of result, install ATTO on a bootcamp partition and do 3 runs of that. Manually run trim before each run.

Also, due to the nature of how SSDs work, speed goes down over time. So, every time you run that test, you age the SSD. The SSD manufacturers design them expecting about 20GB of writes a day. That's really hard to do with usual operations, but that test does 5GB in a few seconds...
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
Well, mine does it too. It's fine. I've had this thing since October 2013, and the SSD has been fine this whole time. If you want the professional level of result, install ATTO on a bootcamp partition and do 3 runs of that. Manually run trim before each run.

Also, due to the nature of how SSDs work, speed goes down over time. So, every time you run that test, you age the SSD. The SSD manufacturers design them expecting about 20GB of writes a day. That's really hard to do with usual operations, but that test does 5GB in a few seconds...

I ran this test for the first time and the same thing happened - even that is normal?
 

theSeb

macrumors 604
Aug 10, 2010
7,466
1,893
none
I ran this test for the first time and the same thing happened - even that is normal?

I watched your video and it's perfectly normal in terms of how the Blackmagic benchmark works. The important numbers are on the right side. Edit: I've just realised that you posted the same video in two threads, so this is a duplicate. My apologies.
 

newellj

macrumors G3
Oct 15, 2014
8,127
3,030
East of Eden
My final number is different each time though? Sometimes I get 500 write sometimes 300.

The write meter jumps up and down and is not smooth in going up like the read is.

This is totally normal with the BM test.

----------

Does this point to my SSD being defective?

The write tests just seem inconsistent and the speed randomly drops and goes higher erratically.

Absolutely not, no it does not.
 

BNHabs

macrumors regular
Original poster
Jul 5, 2010
133
0
This is totally normal with the BM test.

----------



Absolutely not, no it does not.

Watch my video though in this thread, my write will go to 500MB and then drop to 300 in the same test.

Does yours do that? Watch both videos.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.