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SSD speed vs size
- Thread starter Guenter
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Having used the machine for it's intended purpose, which isn't anything strenuous (I have an MBP 16" M3 Max for that), I've decided to stop crying about SSD speed. This little box had dealt with everything I've thrown at it and the disk feels plenty fast, especially as it's the same speed as my MBP 16" i9 MBP (now retired) and much faster than the 500mb/s of the 2014 iMac it's replaced. I'd rather have the 1TB and 32GB RAM than be forced to M4 Pro which I don't need.
Not an option if you want to use Apple Intelligence, it is not available as a service, when the OS is booted from an External Drive.
ATTO has give me strange results on all my tested apple silicon Macs (m1, m2) and seemingly unmatched result for M4 as well:
For Swap out, the number you should be looking for is SEQ 1M QD1, which is a 80% increase 256G->512G on base model.
For Swap in, it might be RND QD1 or RND QD64 or SEQ 1M, details:
(For Swap out)
I checked macOS kernel (although outdated) to confirm this: Darwin might choose to swap any size in between 1-128
(and memory pressure might just be the indicator of QD size) (with some jump reading and guessing, page out ref, correct me if I'm wrong)
swap outs are always going to result in contiguous layout in a swapfile, so it might be better to look at SEQ results on writing.
(For Swap in)
swap ins are RND read however not sure about if it's queued. (anyone interested are welcomed to read the kernel code your self, consider starting from here)
Whether or not you should expect hitting swap to be utilized or a concern really depends on your use case.
If you primarily use your memory for browsing multiple webpages or streaming content, it might be acceptable, and better RND speed does improve performance.
However, if you use your memory for non-linear video editing, Xcode, or even scientific computation, it would not be acceptable.
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There is still something i do not understand. The m4 uses 2 chips regardles of size, the m4pro uses 4 chips from 512 g to 4 t. But what is about the 8 t ssd? Do they also use 4 chips, then apple could use the same chips to offer 4 t on the m4.
On M4 mini:
256GB = 2 x 128GB
512GB = 2 x 256GB
1TB = 2 x 512GB
2TB = 2 x 1TB
On M4 Pro mini:
512GB = 4 x 128GB
1TB = 4 x 256GB
2TB = 4 x 512GB
4TB = 8 x 512GB
8TB = 8 x 1TB
EDIT: the above may be incorrect. The M4 Pro does not seem to be able to support 8 NAND paths, the 8TB config on the mini may be using 2TB NAND modules.
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Those two screen shots don't match because the Amorphous uses 1GB, while the ATTO uses 256MB test file size. Not saying ATTO doesn't behave abnormally sometimes, but the way it logs and present data is more detailed.
In this thread 2t chips are assumed for the 8t ssd
A picture of a card with 8t would show it.
An indication would be the transfer speed of the large ssd.
A picture of a card with 8t would show it.
An indication would be the transfer speed of the large ssd.
Yes that was me who posted the M4 Pro card, seemingly only having 4 NANDs. This new info contradicts the list I posted above, so my list was probably wrong with the 8TB variant of M4 Pro mini.
I did further digging; the following photos and screen shots are from:
Max Tech M4 MBP 512GB vs M4 Pro MBP 14" 512GB
The M4 Pro is using 4 x 128GB to achieve the speed, the visible side only shows 2 NANDs so the other 2 are on the other side, there are no unused soldering pads.
notebookcheck M4 Pro 16" 2TB
The review text noted the 4 NAND modules are 512GB each, the speed test reflects that. All 4 are visible so none are on the other side. Also no unused pads.
We already saw the same pattern in the M3 era of MacBooks, it is safe to assume the M4 Pro SoC does not have enough data lanes for 8 NAND modules. What we need is to visually confirm the 8TB variant of M4 Pro mini uses a daughter card board that looks no different than the one I posted in the other thread, it means Apple are using 4 x 2TB NAND modules, for the first time.
Attachments
I know this thread is mainly about the internal drive, but I also wanted to shared results for the OWC Envoy Ultra 4TB Thunderbolt 5 drive hooked up directly to the Thunderbolt 5 port on back of the M4 Pro Mac mini:
your Pro faster than my Pro in write speed. im getting 4300.
EDIT: nevermind, when i do the 1GB test im getting 5800.
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