NAS and SSD Cache

[Enquiries]

I have a general question about NAS Caching. I am grabbing a Ugreen NAS when they release and know it has two NVME slots that allows for ssds to be used as cache. Is there a ratio of general storage to cache I should be aiming for? Does that ratio change with different raid configurations or use cases? Should I be aiming for as much as I can afford or is there a scenario where too much cache can be less optimal performance-wise?

Just curious on what that relationship looks like, I would imagine there's a sweet spot, between not enough, that requires more turnover in cache that makes it less effective, or too much that is less efficient since it requires more traversal of the cache is required per cache hit, but admittedly, that's sorta based on some speculation that comes from a likely incomplete understanding of how cache actually works, so sorry if this is a stupid question.

Any help or maybe links to existing article would be helpful!

[ed]

When configuring SSD cache for your Ugreen NAS equipped with NVMe slots, it's advisable to tailor your cache size to match your typical daily usage. For most home or media server environments, a cache ranging from 500GB to 1TB proves ample. This size strikes a balance between enhancing read/write performance significantly without unnecessarily overallocating resources.

This strategy ensures an optimal equilibrium between performance and cost-effectiveness, irrespective of whether you employ RAID configurations. Opting for a cache within the 500GB to 1TB range typically yields the most favorable outcomes for the majority of users. Expanding the cache beyond this range might yield minimal performance gains and could potentially result in increased traversal times for cache hits.

For your media server, it's crucial to invest in high-endurance NVMe SSDs capable of enduring heavy read/write operations over time. Seek out SSDs boasting robust DWPD (Drive Writes Per Day) ratings to guarantee durability and dependability. You can access a comprehensive list of recommended NVMe SSDs for caching, along with their respective endurance ratings, on the NAS Compares NVMe List: [https://nascompares.com/answer/nvme-m-2-...wpd-mtbf/).