Is DRAM-less ssds fine? Pros and cons of it?

[GamingSeargent]

Hello, im considering buying a WD Blue SN550 SSD (1TB), and I noticed that it didn't have any DRAM Cache. is this ok, and will it affect the performance of windows boot times and game load times / experience? Thanks!

edit: Here is the product https://www.westerndigital.com/products/internal-drives/wd-blue-nvme-ssd)

[RadiatingLight]

Newer SSDs can sometimes use system RAM instead of a DRAM cache, so research if your SSD supports that.

[mikekir97]

2 minutes ago, RadiatingLight said:

Newer SSDs can sometimes use system RAM instead of a DRAM cache, so research if your SSD supports that.

I was just about to do the same..xD

[GamingSeargent]

Where would they say if it supports it or not?

https://www.westerndigital.com/products/internal-drives/wd-blue-nvme-ssd

[mikekir97]

In Specification but it does not clearly state.. This specific one is considered one of the best DRAM less nvme drives but as Linus explained many times it is recommended to have build in DRAM..  

[GamingSeargent]

on Tom's Hardware (the forum)

i found this spec sheet: 

 

https://www.tomshardware.com/reviews/wd-blue-sn550-m2-nvme-ssd-review-best-dramless-ssd-yet

[TheBean]

Pros to dram-less: $5 cheaper

Cons: low performance, low durability, poor quality, worse warranty

[powerm]

That SSD can't use CPU RAM for caching. The spec you'd be looking for is Host Memory Buffer support to see if it supports that.

[ShadowChaser]

To be fair with the nvme protocol having dram makes less of a difference than on SATA, but having a direct dram cache or HMB would still be preferable to not having anything at all.

[NewMaxx]

On 5/7/2020 at 8:06 PM, GamingSeargent said:

Hello, im considering buying a WD Blue SN550 SSD (1TB), and I noticed that it didn't have any DRAM Cache. is this ok, and will it affect the performance of windows boot times and game load times / experience? Thanks!

edit: Here is the product https://www.westerndigital.com/products/internal-drives/wd-blue-nvme-ssd)

The WD SN550 does quite fine without DRAM, for several reasons. Some above have said HMB but actually the SN500 & SN520 (from which it is derived) do not use HMB.

 

The SN550 is good without DRAM for the following reasons:

1. It has a static-only SLC cache, no dynamic portion. This means it doesn't have to worry about converting to/from TLC/SLC, it doesn't have to force empty/fold (slow) from SLC, and its direct-to-TLC speeds are quite high.
2. It has a relatively powerful controller based on the SN750's tri-core design. The SN750's controller has specialized cores for read, write, host, someone similar to Samsung's NVMe older designs, making it extremely efficient and powerful in cases where the lack of DRAM would hurt - when the drive is fuller, for example. Static SLC also helps in that case.
3. 96L/BiCS4 flash, which is the newest available right now. Not a huge deal but many consumer workloads only hit one die (no interleaving). For this reason the SN550 is actually a bit faster than the SN750 (64L/BiCS3) in consumer use, e.g. game loading.
4. It relies on the NVMe protocol vs. AHCI (SATA drives) which is superior for solid state (flash) devices including being more efficient. This means it can finish tasks faster and more efficiently which reduces the metadata load. Garbage collection (GC), a form of maintenance, often bogs down without DRAM but again, fast controller and static SLC as mentioned above.
5. The controller still has embedded SRAM of which some (more than typical) can be used for traditional DRAM tasks. Other DRAM-less controllers like the Phison S11 (SATA) also do this but, in combination with the rest of the list, makes the SN550 capable of handling larger workloads, as can be seen even with the older SN500 in AnandTech's review.

By far and large the 1TB SN550 is seen as a value champion right now.