Dynabook Portege Z40L-N exhibits similar SSD throttling issues as its predecessor

The Dynabook Portege Z40L-N is now widely available for business users looking for a superlight 14-inch laptop. Its portability makes it an attractive option for travelers, but it comes at a cost as previously discussed. Unfortunately, additional compromises have also been made in order to attain the <1 kg target.

As shown by our DiskSpd stress test results below, the Phison C-E80T001T2 PICe4 x4 NVMe SSD in the Portege Z40L-N suffers from throttling after just a minute into the test. Transfer rates would start out at almost 7000 MB/s which is close to the real-world maximum performance of PCIe4 x4 SSDs before fluctuating down to as low as 2300 MB/s thereafter.

The Samsung PM9A1 in the older 2022 Dynabook Portégé X30L-K would exhibit even more extreme throttling issues as well with performance levels as low as 1700 MB/s when running the same stress test.

A major contributing factor to the throttling SSDs is how these Dynabook models prioritize lighter weight over performance. There is no cooling solution or heat pads for the drives to dissipate heat and so the SSDs can only maintain high performance levels for so long before reaching temperature thresholds. Heavier 14-inch laptops like the Dell Pro 14 Premium are much less likely to suffer from similar SSD throttling issues.

Users can check out our review on the Dynabook Portege Z40L-N for more benchmarks and performance comparisons.