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2018 MBP SSD Speed & Benchmarks

RobbieTT

RobbieTT

macrumors 6502a
Original poster
Apr 3, 2010
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United Kingdom
Setting aside all the 'up-to' SSD speeds claimed for the 2018 MBP I was wondering what people are getting on an in-use MBP once part-filled and if the quicker CPUs make a difference. A colleague of mine is getting the same SSD speeds on his 512GB i9 that I am getting on my base 13" i5 with the same size of SSD. We are both running FileVault but with T2 I don't think this should impact benchmarks.

My 13" i5 16GB RAM, 512GB SSD (1846MB/s Write, 2530MB/s Read):

DiskSpeedTest.png

Clearly just a curiosity as the SSDs are quick in any guise.
 
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jerryk said:
Bottom line looks to be bigger SSDs are faster.

But we have know that for a long time.
Click to expand...

That is true, larger SSDs usually have more NAND chips than the smaller ones.

On a side note, the main bottleneck for the Mac is the GPU now.
 
So,
-256 SSD 1400 MB/s Write 2200 MB/S Read
-512 SSD 1846 MB/s Write 2500 MB/S Read
-1T SSD 2500 MB/s Write 2600 MB/S Read
-2T SSD 2600 MB/s Write 2700 MB/S Read
-4T SSD 2650 MB/S Write 2800 MB/S Read
 
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Pangalactic said:
That is true, larger SSDs usually have more NAND chips than the smaller ones.

On a side note, the main bottleneck for the Mac is the GPU now.
Click to expand...

Partially true. It would be totally true when comparing same brands but that is not the case. If you’ve noticed, the 512 and 256 have 1/2 the write speed of the 1 TB+. That’s because Apple is using the same Samsung SSDs it used in 2017 MBPs while using Toshiba for the 1 TB+.

Apparently the Toshiba one is much faster. Someone on Apple discussion forums claim that Apple is also using SanDisk for some 1 TB+ drives and it’s even faster.

fokmik said:
So,
-256 SSD 1400 MB/s Write 2200 MB/S Read
-512 SSD 1846 MB/s Write 2500 MB/S Read
-1T SSD 2500 MB/s Write 2600 MB/S Read
-2T SSD 2600 MB/s Write 2700 MB/S Read
-4T SSD 2650 MB/S Write 2800 MB/S Read
Click to expand...
 
M.Rizk said:
Partially true. It would be totally true when comparing same brands but that is not the case. If you’ve noticed, the 512 and 256 have 1/2 the write speed of the 1 TB+. That’s because Apple is using the same Samsung SSDs it used in 2017 MBPs while using Toshiba for the 1 TB+.

Apparently the Toshiba one is much faster. Someone on Apple discussion forums claim that Apple is also using SanDisk for some 1 TB+ drives and it’s even faster.
Click to expand...
- No, for two reasons:
1) Apple doesn't use whole SSDs from particular brands. They use NAND chips from one or more suppliers in combination with their own controller (the T2). And the controller (which is the same across all models) is at least as important as the NAND for speed.
2) iFixit's teardowns show Toshiba flash on both the 2018 13" and the 2018 15" in the 256 GB size.

(Also, 1800 isn't 50% of 2500. It's ~70%.
And a difference of a factor of roughly 2 or a bit lower in sequential write speed is quite normal between ~500 GB and ~1 TB versions of the same drive.)
 
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JTToft said:
- No, for two reasons:
1) Apple doesn't use whole SSDs from particular brands. They use NAND chips from one or more suppliers in combination with their own controller (the T2). And the controller (which is the same across all models) is at least as important as the NAND for speed.
2) iFixit's teardowns show Toshiba flash on both the 2018 13" and the 2018 15" in the 256 GB size.

(Also, 1800 isn't 50% of 2500. It's ~70%.
And a factor of roughly 2 or a bit lower in sequential write speed is quite normal between ~500 GB and ~1 TB versions of the same drive.)
Click to expand...

Interesting find. Thanks for sharing the link.

Unfortunately I was basing my info based on what a member on Apple discussion forums claimed being told so by Apple Care.

Why does the 256 have a very close write speed to the 512 then? And why is the difference between the write speed on the 512 and 1 TB double yet not much of a difference between 1 TB, 2 and 4? :/
 
M.Rizk said:
Interesting find. Thanks for sharing the link.

Unfortunately I was basing my info based on what a member on Apple discussion forums claimed being told so by Apple Care.

Why does the 256 have a very close write speed to the 512 then? And why is the difference between the write speed on the 512 and 1 TB double yet not much of a difference between 1 TB, 2 and 4? :/
Click to expand...
- Don't believe everything you read. ;)
I haven't seen anything other than Toshiba flash on the 2018 models. But even if Samsung or SanDisk is also used, there's no reason to believe it makes a difference for performance.

The parallelism which gives larger SSDs the advantage over smaller ones normally isn't as pronounced between 256 and 512 GB, while it typically tapers off above 1 TB. 512 GB vs 1 TB is the largest difference. It has to do with the number and density of NAND dies.
 
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JTToft said:
- Don't believe everything you read. ;)
I haven't seen anything other than Toshiba flash on the 2018 models. But even if Samsung or SanDisk is also used, there's no reason to believe it makes a difference for performance.

The parallelism which gives larger SSDs the advantage over smaller ones normally isn't as pronounced between 256 and 512 GB, while it typically tapers off above 1 TB. 512 GB vs 1 TB is the largest difference. It has to do with the number and density of NAND dies.
Click to expand...

I agree. Performance increase on size is based more on having more modules that can be written to in parallel.
 
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Really impressive performance from a portable drive. I still find it hard to comprehend the increase in drive speeds we have experienced over the last few years.
 
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