SLC Cache

[raid25885]

For Samsung SSD 980 1 TB, according to its specs, it has 160 GB for Max SLC Cache Size ? Is that accurate ? Does it mean it can write huge files almost instantly ?

[SorryBella]

12 minutes ago, raid25885 said:

it has 160 GB for Max SLC Cache Size ?

at 0% after formats. DRAMless SSD has no true cache, those 160GB are overprovisioned TLC cells acting as SLC (as in they have the privilege of only doing 1 cell write instead of 3), and shrink as your drive fills up overtime. But as long as you dont exceed that 160GB? the write should be at its maximum pace. This curve made by TechPowerUp explains it better, in a scenario where its filling the drive with 1MB of file until the drive is full.

 

But even with the fact that average write speed overtime is equal to SATA 3, the read and data latency is where Nvme truly shines. Thats the difference between the time your CPU asks for a data from the SSD until your CPU recalls it back to the SSD. SATA 3 is just that inefficient, the difference is tangible in a data intensive task like Machine Learning and high resolution video editing.

[raid25885]

May I ask what determines that 2500 MB/s speed in that SLC cache, how come it does not say it the 980 ssds specs ?

[SorryBella]

On 8/19/2023 at 10:15 PM, raid25885 said:

May I ask what determines that 2500 MB/s speed in that SLC cache, how come it does not say it the 980 ssds specs ?

Specs of an SSD is just straight up the most useless thing on earth. So much variables affect an SSD performance that reading it alone does nothing to clear the confusion on which is more reliable faster or better in value. Ignore it and run straight for reviews.