SSD class 35 vs 40 or Class 35 vs class 40 SSD – Which is better?
SSD aka Solid State Drive is one type of storage device that can work by replacing the hardware. It is like the replacement of the hardware of a computer. The interconnected flash memory chips are the main parts SSD uses to store data. It’s use makes one’s computing reliable and faster at the same time. These memory chips are on the small box circuit of the SSD. Even though the primary purpose of all SSD is to keep memories, they are all different considering their features. Its SATA connection, PCIe slot connection, speed, or M.2 connector as well. These things make an SSD different from another one.
There has been a new term Class that Dell has come up with. At first, the users didn’t know what this class indicates and what is the difference between each class. Such as Class 10, Class 20, Class 35, or Class 40. What makes them different and which one is better than the other? These questions have continuously aroused people. Now let’s dig into it and see which one is better between SSD class 35 and SSD class 40.
What does SSD Class mean?
Class is one type of grading system that the Dell company first came up with. Since SSDs performance differentiation can be difficult sometimes when adding the firmware or the controller, this grading system is like a savior.
Class means to rate the speed of the disk. The higher you go, the faster it will be. Moreover, the interface also improves by getting a higher class.
Class | Connector | Marketing | Sequential Read/Write | Random Read/Write | Interface |
10 | SATA | Value | 520 MBps/320 MBps | 30 MBps/10 MBps | SATA [Dram-less] |
20 | SATA | Mainstream | 500 MBps/300 MBps | 80 MBps/60 MBps | SATA |
30 | SATA | Performance | 550 MBps/350 MBps | 90 MBps/75 MBps | High-performing SATA |
35 | PCIe | Performance | 800 MBps/1200 MBps | 95 MBps/- | NVMe [Dram-less] |
40 | PCIe | Performance | 1500 MBps/ 350 MBps | 200 MBps/80 MBps | NVMe PCIe |
The higher the number of Classes is, the more reliable and fast it is. That’s why when comparing, the higher SSD classes become superior.
Class 35 SSD vs Class 40 SSD
If we see the main grading system Class defines, SSD 40 is faster and better. Class 35 uses a single module or NAND flash memory. Since NAND, multiple layers do not require power or other means to store data, it is convenient and has better means. It uses NVMe but that is DRAM-less. To replace DRAM, class 35 SSD offers HMB. HMB stands for Host memory buffer. Its sequential read is 800 MBps and its write is 1200 MBps. The random read is somewhat near 95 MBps.
On other hand, Class 40 has multiple NAND modules. The more module an SSD has, the faster it works. That’s why class 40 has a fast speed and better storage performance. The NVMe PCIe interface it features has DRAM. Its sequential read and write are respectively 1500 and 350 MBps. The random read and write are 200 MBps & 80 MBps.
While comparing the module, speed, readings, and interfaces, Class 40 SSD is better than 35. That does not mean Class 35 is not on par. Just a few differences made it happen. However, Class 35 is cheaper and offers faster performance, though not as much as 40 class SSD.
Frequently Asked Questions
- Is SSD 35 class better than 40 class SSD?
In terms of price to performance, class 35 is a good choice. But we know the higher the class, the faster and better performance we get. That's why SSD class 40 is better than the 35 class.
- What does SSD class mean?
Class is one type of grading system that the Dell company first came up with. Class means to rate the speed of the SSD. The higher you go, the faster it will be. Moreover, the interface also improves by getting a higher class.
- Is SSD class 30 better or SSD class 40?
The increase in class number, the better performance, and efficiency. Class 30 uses a high-performing SATA interface which is why it has quite a big cost for manufacturing. When other high classes were released with much better performance that cost less manufacturing, the 30 class has been on the lower side. SSD class 40 offers even better performance with its PCIe NVMe and has a reasonable price unlike class 30. That's why SSD class 40 is better than SSD class 30.
- What is the difference between Class 35 and Class 40 solid state drive?
The difference between class 35 and class 40 solid state drive is different NAND modules and performance as well. Class 35 uses a single module or NAND flash memory. It uses DRAM-less NVMe and rather uses HMB. On the other hand, Class 40 SSD uses multiple NAND modules. The more module an SSD has, the faster it works. That’s why class 40 has a fast speed and better storage performance. It uses an NVMe PCIe interface with DRAM. In terms of pricing, SSD 40 is slightly pricier than the 35 one.

Frintz is a tech maniac and has been handling tech products for a long time which helped him gain experience.