MacMini Flash Storage: Poor Write Speed?


msh

macrumors 6502
Original poster
Jun 13, 2009
331
107
SoCal
"Larger SSDs sometimes use more NAND chips, which means that more data can be written to more places at once, which greatly benefits write performance in particular."

https://arstechnica.com/video/2016/11/the-2016-13-and-15-inch-touch-bar-macbook-pros-reviewed/4/
I knew smaller capacity ones could be slower at writes but half the read speed? That arstechnica article shows 4 256GB SSDs and only one of them has write speed half that of read speed. I guess on an absolute basis not that big a deal as 1200/1400 MB/s write is still plenty fast.
 
Last edited:

xylitol

macrumors 6502
Nov 2, 2013
270
45
Finland
I just wish Apple was more open about these (and many other) things, especially considering that the write speed of 128GB SSD seems to be pretty lame.
 
Last edited:
  • Like
Reactions: DVD9

Spectrum

macrumors 65816
Mar 23, 2005
1,336
700
Never quite sure
I find the singlecore Geekbench score for the 5K iMac to be beyond belief... nearly 7000?

How is that possible when the CPU is 7th generation with a max turbo of 4.5 GHz?

To compare, the fastest scores posted for the i7 Mac mini ( 8th Generation and max turbo of 4.6Ghz) are ~6000.
 

msh

macrumors 6502
Original poster
Jun 13, 2009
331
107
SoCal
Barefeats has now revised their review and included a mini with a 512GB flash drive and - surprise? - the larger drive has much better write speed (1876 vs 1200). So best get at least a 512GB for optimal write performance.
 
  • Like
Reactions: ElectronGuru

Ice Dragon

macrumors 6502a
Jun 16, 2009
984
20
Barefeats has now revised their review and included a mini with a 512GB flash drive and - surprise? - the larger drive has much better write speed (1876 vs 1200). So best get at least a 512GB for optimal write performance.
This is what I am going to do. I would go a 1 TB if I could but I don't want to spend too much money. 16 GB of RAM and a 512 GB SSD will last me several years.
 

archer75

macrumors 68030
Jan 26, 2005
2,698
1,235
Oregon
Barefeats has posted a test of the mac mini i5 and finds substandard write speed for the flash storage as a result of thermal throttling.

http://barefeats.com/mac-mini-2018-versus-other-macs.html
No, they did not say it's a result of thermal throttling, which would make no sense by the way.

"In the storage test, what first appeared to be thermal throttling on the Mac mini with the 256G flash storage is more likely a "feature." In other words, if you want the best possible large sequential WRITE speed, you much choose the 512G or 1TB option."

Basically, you get better performance from larger storage options as the Ars articles states.
 

msh

macrumors 6502
Original poster
Jun 13, 2009
331
107
SoCal
No, they did not say it's a result of thermal throttling, which would make no sense by the way.

"In the storage test, what first appeared to be thermal throttling on the Mac mini with the 256G flash storage is more likely a "feature." In other words, if you want the best possible large sequential WRITE speed, you much choose the 512G or 1TB option."

Basically, you get better performance from larger storage options as the Ars articles states.
The original article made the thermal throttling claim. The revision reversed that.
 

Spectrum

macrumors 65816
Mar 23, 2005
1,336
700
Never quite sure
Intriguing why write is still slower than the tested MBPro with 512Gb...

Also interesting that the iGPU differences between i5 and i7 are measurable:
upload_2018-11-21_16-33-26.png


Also: Rob updated the singlecore result for the 5K iMac...
 
Last edited:
  • Like
Reactions: ElectronGuru

mrex

macrumors 68040
Jul 16, 2014
3,284
1,350
europe
Intriguing why write is still slower than the tested MBPro with 512Gb...

Also interesting that the iGPU differences between i5 and i7 are measurable:
View attachment 805705

Also: Rob updated the singlecore result for the 5K iMac...
the difference between max freq. between i5 (8500b) and i7 (8700b) igpu is 100mhz (extra for i7). also the i7 system had more memory - 8 vs 16gb - to share.
 

Nsmn

macrumors newbie
Nov 25, 2018
4
0
Wait, what if I got a mini with i7 with 128 ssd and external tb3 ssd (Samsung x5 1tb for example)

The write speed would be faster for the external then the internal one?
 

Spectrum

macrumors 65816
Mar 23, 2005
1,336
700
Never quite sure
Wait, what if I got a mini with i7 with 128 ssd and external tb3 ssd (Samsung x5 1tb for example)

The write speed would be faster for the external then the internal one?
Yes. But if you are mostly just using the internal as a boot drive, this shouldn't make much if any difference. And it is still >2x fast as the fastest internal SATA SSD, which were already 2-3x as fast as the fastest internal HDD.
 

Nsmn

macrumors newbie
Nov 25, 2018
4
0
Yes. But if you are mostly just using the internal as a boot drive, this shouldn't make much if any difference. And it is still >2x fast as the fastest internal SATA SSD, which were already 2-3x as fast as the fastest internal HDD.
Does it mean, with limited budget, i7 128 ssd is a better deal than i5 256ssd if using tb3 external ssd?
 
Last edited:

MacWorld78

macrumors 6502
Jul 25, 2012
426
181
Does it mean, with limited budget, i7 128 ssd is a better deal than i5 256ssd if using tb3 external ssd?

Well, if you use TB3 to TB3 via external NVMe storage - the data can go max speed according to the NVMe's Specification. Max speed would be anything under 40 Gbps via TB3.