SSD Cache on Synology NAS: How It Improves Performance
The SSD cache on a Synology NAS is meant to make the system more responsive and lower the latency for data that is accessed often. Instead of replacing hard drives, SSD cache works with traditional HDD storage to speed up reading and writing, especially when there are a lot of users or metadata-heavy workloads.
Organizations can decide whether SSD cache is worth the money by learning how it works and when it really helps.
What SSD Cache Does for Synology NAS
Instead of slower spinning disks, SSD cache stores data blocks that are accessed often on fast solid-state drives. When the NAS sees the same access patterns over and over, it serves that data directly from the SSD. This speeds up access and makes the whole system more responsive.
Synology lets you set up SSD caches that can be read-only or read-write. Read-only cache speeds up access to data without putting it at risk, and read-write cache can speed things up even more by holding off on writing operations until they are saved to hard drives.
SSD Cache Works Best with These Workloads
SSD cache works best with workloads that have random I/O patterns instead of big sequential transfers. The most noticeable improvements are usually seen on file servers that have a lot of users opening small files, databases, virtual machines, and collaboration platforms.
Operations that use a lot of metadata, like browsing large file directories or searching shared folders, also get a lot better. On the other hand, SSD cache doesn’t help much with big media streaming or backup jobs that require sequential reads and writes.
Cache that can only be read vs. cache that can be written to
The safest and easiest choice is a read-only SSD cache. It speeds up data that is accessed often without changing how writes are handled, making it perfect for general file sharing and workloads that need a lot of reading.
Read-write cache gives you better performance, but it needs redundancy. To avoid losing data if an SSD fails, Synology suggests using mirrored SSDs for read-write cache. This setup works best in high-performance settings where low latency is very important.
NVMe SSD Cache vs. SATA SSD Cache
Many of the newer Synology NAS models have NVMe SSD cache, which has much lower latency and higher throughput than SATA-based SSDs. NVMe cache works especially well in systems that have to deal with a lot of small transactions or virtualization workloads.
SATA SSD cache is still useful, but it’s better for small performance boosts than for heavy enterprise workloads.
Realistic Performance Goals
SSD cache makes things respond faster, but it doesn’t speed up the network itself. It doesn’t make a gigabit network into a multi-gigabit one, and it doesn’t speed up file transfers by a lot. Less time spent waiting, a smoother user experience, and better concurrency under load are the biggest benefits.
The performance benefits also get better over time as the cache learns how people use it. At first, the gains may not be very big right away.
When SSD Cache Might Not Be Needed
SSD cache isn’t necessary for every NAS setup. Single-user systems, media servers that only stream in order, and backup-only targets usually don’t see much of a measurable benefit. In these situations, putting money into more RAM or faster networking might pay off better.
Best Ways to Use SSD Cache
Sizing correctly is important. A cache that is too small doesn’t work as well, and a cache that is too big doesn’t work as well either. For reliable handling of heavy workloads, it is best to use enterprise-grade SSDs with high endurance ratings.
Using Synology DSM to keep an eye on cache hit rates helps you make sure the cache is working and helps you plan future improvements.
SSD Cache as a Part of a Bigger Plan to Improve Performance
You should think of SSD cache as just one part of how well your NAS works. Real-world results are affected by things like network bandwidth, RAID setup, drive health, and memory allocation. When put together in the right way, these parts make a storage system that is balanced and works well.
About the Epis technology
Epis Technology offers enterprise IT infrastructure, data protection, and Synology consulting services that help businesses get the most out of their NAS in terms of performance and scalability. The business’s main areas of expertise are Synology storage architecture, planning SSD caches, optimizing backups, and tuning system performance. Epis Technology makes sure that businesses get real performance gains without adding unnecessary complexity by aligning SSD cache design with real workloads.