Longsys shows what DDR5 is capable of
In July 2020, JEDEC, the Solid State Technology Association, officially published the DDR5 SDRAM standard. The Chinese NAND flash manufacturer Longsys is currently working on two DDR5 modules. Their tests show all the new standard has to offer.
Thanks to an Alder Lake S processor, using the 12th Intel core generation, Longsys was able to present the first results of their RAM. Both DDR5 modules under development are of the DDR5-6400 type. The 16 GB variant comes in a single-rank design and the 32 GB in a dual-rank design. Furthermore, both have an eight-layer PCB, a CAS latency (CL) of 40 and 1.1 V of DRAM voltage. With DDR5, transfer rates of up to DDR5-8400 and up to 128 GB of memory per module should be possible.
The results
In the AIDA64 Cache & Memory benchmark, the Chinese manufacturer pits a 32 GB DDR5 RAM against a 32 GB DDR4 RAM. The CL of the DDR5 bar is 40, that of the DDR4 bar 22. As a result, the latency in the test is also higher with DDR5 RAM than with DDR4. However, this is normal – the latency was also significantly higher at the beginning of the switch from DDR3 to DDR4.
| Longsys DDR5 32GB | Longsys DDR4 32GB | Difference (in per cent) | |
|---|---|---|---|
| AIDA 64 Read | 35844 MB/s | 25770 MB/s | +39 |
| AIDA 64 Write | 32613 MB/s | 23944 MB/s | +36 |
| AIDA 64 Copy | 28833 MB/s | 25849 MB/s | +12 |
| AIDA 64 Latency | 112,1 ns | 56,8 ns | +97 |
The test ran on a developer board from Alder Lake-S. The eight-core processor operated with a fixed clock of 805.8 MHz during the test. The increase in performance is considerable at up to 39 per cent. However, latency is also significantly worse with DDR5: DDR4 memory reacts almost 100 per cent faster.
DDR5 should become accessible to a broad audience with Intel's Alder Lake S processors. They'll be out around late 2021 or early 2022. AMD hasn't yet announced anything about DDR5.
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