QNAP | NAS | ALL-FLASH SERIES | MEMORY UPGRADES
ECC memory for QNAP all-flash NAS platforms — the TS-h AFU and ES-series systems built entirely on SSDs rather than spinning disks.
All-flash changes what the memory has to do. With no seek latency to hide behind, the bottleneck moves to the controller, and ZFS-based QuTS hero — which QNAP runs on these units — uses RAM as its ARC read cache and for deduplication tables. More memory is not a nice-to-have on an all-flash NAS; it is what lets the flash perform. QNAP's own guidance for dedup workloads runs to gigabytes of RAM per terabyte of storage.
all QNAP part numbers cross-referenced, all ECC: registered RDIMM for the rackmount and ES enterprise units, ECC UDIMM for the tower models. DDR4 at 2666MHz and 3200MHz, from 8GB to 64GB per module.
ECC is not optional here. These platforms are specified for it, and QNAP's part numbers carry EC in the middle to mark it — RAM-32GDR4ECT0-RD-3200 is ECC registered; a code without those two characters is a different module that will not work.
Match by part number above, or see the full QNAP NAS Memory Cross-Reference for the complete range. Lifetime warranty on every module. Purchase orders, net terms and volume pricing for business, government and education buyers.
The all-flash lineup and what each unit takes
| Model | Processor | Ships with | Slots | Memory | Documented max |
|---|---|---|---|---|---|
| TS-h1090FU | AMD EPYC 7232P / 7302P | 32GB or 128GB | 8 | DDR4-3200 ECC RDIMM | 512GB (8×64GB) |
| TS-h2490FU | Dual AMD EPYC 7302 / 7402 | 128GB or 256GB | 16 | DDR4-3200 ECC RDIMM | 1TB (16×64GB) |
| TS-h1290FX | AMD EPYC 7232P / 7302P | 64GB or 128GB | 8 | DDR4-3200 ECC RDIMM | 512GB (8×64GB) |
| TDS-h2489FU | Dual Xeon Silver 4214 / Gold 5218 | 128GB or 256GB | 16 | DDR4-2933 ECC RDIMM | 1TB (16×64GB) |
| ES2486dc | Xeon D-2142IT per controller | 96GB per controller | 6 per controller | DDR4-2666 ECC RDIMM | 128GB per controller |
| ES1686dc | Xeon D-2123IT per controller | 32GB or 64GB per controller | 4 per controller | DDR4-2666 ECC RDIMM | 128GB per controller |
Shipped configurations vary by SKU; the figures are QNAP's published ones. The DDR5 all-flash units — TS-h1277AFX and TS-h3077AFU on Ryzen 7000 with DDR5 ECC UDIMM — are the next generation and are listed on the full QNAP cross-reference under their own part numbers.
Sizing memory for an all-flash QuTS hero unit
On a spinning-disk NAS, RAM caches around disk latency. On all-flash there is no latency to hide, so the ARC's job becomes serving metadata and hot blocks at memory speed while the SSDs handle everything else — and the pool-management features that make QuTS hero worth running are the ones that consume it. Rough sizing that holds up in practice:
- Baseline: 16GB is QNAP's practical minimum for QuTS hero; 32GB is the sensible floor on any all-flash unit doing real work.
- Pool size: about 1GB of RAM per TB of usable pool for ARC to stay effective — a 100TB flash pool wants 128GB before anything else is running.
- Inline deduplication: the dedup table lives in RAM. QNAP's guidance is 1GB to 5GB per TB of deduplicated data depending on block size; a 50TB deduplicated pool on the high end is 256GB. If the unit will run dedup, size for it or turn it off.
- Compression: cheap in CPU and memory; does not change the sizing.
- iSCSI / NVMe-oF / 25–100GbE targets: each LUN and each high-speed session holds queue and buffer memory. Add 8GB to 16GB for a busy block-storage role.
- Virtualization Station and containers: whatever the guests need, on top.
The consequence: a TS-h1090FU at its 32GB base configuration serving a 60TB flash pool with dedup on is memory-starved from the first day, and the symptom looks like slow SSDs. Bringing it to 128GB or 256GB is what makes the flash perform, which is what the intro above is saying.
Population rules on these platforms
- RDIMM only. Every unit on this page is a registered-memory platform; the EC + -RD code is the whole spec. LRDIMM is not on QNAP's list for these units and does not mix with RDIMM.
- Fill channels before doubling up. EPYC 7002 has 8 memory channels per socket. The 8-slot FU / FX units run one DIMM per channel — populate all eight for full bandwidth; a four-module upgrade leaves half the channels idle. The 16-slot dual-socket units are 8 per CPU.
- Balance both sockets. On the TS-h2490FU and TDS-h2489FU, populate both processors identically; an unbalanced layout leaves one CPU without local memory.
- Match capacity, speed, and rank. Mixed speeds run at the slowest module; mixed ranks within a channel can force a lower speed. Identical modules across the system — which for an 8-channel EPYC means a kit of 8 — is the safe configuration, and it is why this page sells matched sets.
- The CPU sets the speed. EPYC 7002 runs DDR4-3200; Xeon Silver 4214 runs 2400 and Gold 5218 runs 2666 regardless of a 2933 module; Xeon D-2100 runs 2400 or 2666 by SKU. QNAP lists the module speed the unit was qualified with; that is the part to buy.
- Dual-controller ES units. Both controllers must carry identical modules in identical slots or failover does not synchronize. Upgrades are bought and installed in matched sets of two, one per controller.
How to check what is installed
- QuTS hero → Control Panel → System → System Status → Hardware Information shows installed capacity, slot population, module speed, and ECC status. On the ES units, QES → System Status shows the same per controller.
- QNAP's compatibility list for the model lists the RAM- parts, slot count, and documented maximum.
- The module label carries capacity, speed, rank, and the ECC / registered markings.
Why a tested module here
These are the units where a wrong or marginal module costs the most — a registered platform behind a NAS BIOS, fully populated, running ZFS against 100GbE. Every NEMIX RAM module on this page is Specc'd on Micron, Samsung, or SK hynix DRAM to the specification of the QNAP RDIMM it replaces, and run in the platform class it is listed for before it is offered. Sets are sized to the channel count so every slot receives an identical module. Lifetime replacement warranty and free US-based support on every module.
Ordering for deployments
All-flash QNAP units are bought in pairs and racks more often than singly. NEMIX RAM is a registered federal supplier (UEI GV8MMYNDJ5J1, CAGE 59AB2) and accepts purchase orders with net terms for business, government, and education buyers. Send the models, unit count, and target capacity per unit to our sales team and we return one quote with a matched set per unit, controller pairs called out on the ES units. Volume and reseller pricing is available on request.
Frequently asked
Can I add four modules to my TS-h1090FU instead of eight? It will run, at half the memory bandwidth, and QuTS hero will feel it under load. If the budget allows only four now, buy four of the same module you will finish the set with.
Can I use RAM-32GDR4ECT0-UD-3200 (ECC UDIMM) in a TS-h1290FX? No. The FX is a registered platform; the -RD part is the only one that fits. UDIMM and RDIMM are different sockets electrically.
Do I need L2ARC or SSD cache on an all-flash unit? No — the pool is already flash. Spend the money on RAM; that is where the cache belongs on these units.
How much RAM for dedup on a 40TB pool? Plan 40GB to 200GB for the dedup table alone depending on block size and data, on top of the baseline. If that is more than the unit can hold, run compression without dedup.
Does upgrading void the QNAP warranty? QNAP documents memory as user-upgradeable and publishes compatible modules. Adding memory does not void the NAS warranty; our lifetime warranty covers the module.
NEMIX RAM can deliver any Configuration your Fleet Requires
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