Slow internal ssd speeds MacBook Pro M4 Pro

As I read your posting, the results for M1 and M4 appear to be comparable.

That is neither remarkable nor surprising. SSD drive technology has not changed in the time since the first model was introduced..

As long as RAM bandwidth is available (and Both the Apple-silicon Macs you mention have HUGE memory bandwidth) SSD speeds should be comparable, and they are.

Transfers to and from SSD drives (and transfer to your display as well) each use a Hardware Automaton to complete the actual data movement. These data rates are HUGELY faster than one-word-at-a-time processor transfers can possibly support. Processor speed and number of processor does not figure into drive speed in any measurable way.

[in my opinion] there is no defect in your Mac, and you have no complaint.

Those speeds are so fast that for most tasks, sequential read/write performance is not going to be a bottleneck.

One of two things will be true:

• The amount of data to be transferred will be small enough that 5129.9 MB/s or 4220.3 MB/s is "instantaneous" (given human reaction times) and that further increases in speed would produce no perceivable improvement.
• There will be things other than raw sustained sequential read/write speed (such as Finder overhead) which are responsible for much, or all, of the perceived delay.

If I launch LibreOffice on a M1 Max Mac Studio, the application starts up quickly – but not instantly. I can see the icon bounce a couple of time in the Dock, and then there is a slight delay before I see the startup window.

According to this AppleInsider article, a M1 Max Mac Studio with a 512 GB SSD had a read speed of 5180.3 MB/s, and a write speed of 4629 MB/s, on the BlackMagic disk speed test. Finder reports that my copy of LibreOffice takes up 781,177,995 bytes – or 825 MB on disk (since disk space is allocated in blocks).

If all that was involved in launching LibreOffice was to sequentially read a large block of data off of the SSD at the fastest speed possible, that would imply that the application would launch in about 1/6.3rd of a second. Clearly it takes much longer than this to launch the application (the first time; caching can speed subsequent launches) … and so there's something going on other than just reading a big sequential data block as fast as possible.

I haven't read how the new M4 MacBook Pro's SSD are configured, but I recall reading about how the Mac Studio's disk performed more slowly on the base configuration because the smaller SSD used a single chip instead of multiple. I wasn't able to find any article that describes the M4 MacBook Pro various SSD configurations but could this be a factor?

FWIW, as a reference, my M4 Max MBP, with 2T SSD' Black Magic shows around 5200 MB/s Read and between 6800 - 8400 MB/s Write (5G vs 1G).

You did not buy (and pay the Premium for) the 2TB model. if you did, I expect it would also be faster.

Your drive is not defective, and at the speeds you are getting, you have no complaint.

I could send you a high-end Rotating magnetic drive to use instead. it consistently test above 100 M Bytes/sec reading, about half that writing.

the bigger the faster m3 max with 1tb as beyond 6000

Maybe it's a dud. Return it for replacement.

one more thing:

if you bought DIRECT from Apple, not from a Reseller of any description, you have 14 days from Receipt to return/exchange your purchases for a full-value refund/exchange.

This is the only remedy Apple offers, but it covers a Multitude of disappointments.