About the fastest solid state drive that has the speed of RAM and consists of it

overclockers.ru

3 min

May 21, 2023

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Computer technology is developing very rapidly, all its components are developing at approximately the same speed, and plus or minus, they correspond to each other in terms of performance. But there is one component that always lags behind the rest in development and always has insufficient performance - this is the disk subsystem. And whatever the performance of the central processors, no matter how many cores they have, no matter how fast the RAM is, they will not be able to realize their performance with an extremely low-performance disk subsystem. When it becomes necessary to read from or write to the hard disk, there is a delay, and regardless of the performance of all other components, they are forced to idle, which leads to a decrease in the performance of the entire computer.

And even modern, fairly fast NVMe SSD drives, which are simply grandiosely superior in speed to HDDs, are not able to fully provide the necessary performance to the disk subsystem. They do have the highest speed though. But if you delve deeper into this issue, it turns out that this is not entirely true. Their speeds are high only when sequentially reading and writing large files. And when working with small files, their speeds, unfortunately, are still depressingly low. And loading an operating system or other software is working mainly with small files.

Throughout the evolution of the development of computers, developers have constantly been working to create drives, the speed of which would allow to fully realize the performance of other components. And so, one day, a group of applicants came up with a brilliant idea. You can also take RAM, which is the fastest memory in computers, insert it into some kind of adapter and shove a controller into it to match the motherboard. Well, insert another battery to ensure the safety of information when this device is de-energized.

As they say, said is done. Gigabyte created the first such drive called "Gigabyte I-RAM" in 2005.

It consisted of a board with a PCI slot for installation in the motherboard. Moreover, the PCI slot was used only to power the drive, no data exchange was carried out through it. For the exchange, the first generation SATA interface was used, the slot of which was located in the upper part of the board. The board had four DIMM slots for installing first-generation DDR RAM sticks in them operating in single-channel mode. There was also a chip with a SATA controller and a DDR memory controller. Well, a battery with a voltage of 3.7V to provide power to the drive when it is de-energized in order to save data.

The battery capacity is enough for 16 hours of autonomous power supply of the device, after which, in the absence of external power, the battery is completely discharged, and the data is irretrievably lost. This drive had a speed of 130 MB / s, almost the upper limit of the throughput of the SATA-1 interface. The speed, of course, is not so hot, but the access delay is 0.1 µs versus 100 µs in modern SSDs. This device only works with 1GB memory sticks. In total, a 4 GB drive is obtained, which is very modest, but let's not forget that these are only the first models.

Model with DDR3 memory

The upgraded model DDRAM-Disk v2.0 of 2022 already has 14 slots for DDR3 memory on its board. It works with 4 GB sticks in dual-channel mode. In total, the drive has a total capacity of 56GB, which, of course, is already much larger, but still very modest.

For data exchange, the PCIe 4.0 x 8 bus and the NVME 1.3 exchange protocol are already used here, the chip is used by Silicon Motion SM2264. The speed of this drive is shown below.

Model with DDR4 memory

The next model DDRAM-Disk v3.0 has 18 slots for DDR4 memory. The memory of the drive is 72GB. The exchange protocol is the same as in the previous model. The speed of the drive is simply cosmic, up to 15GB / s for sequential reading and writing, and up to 3.8GB / s for random. The cooling of the controller is already active here, since the passive one cannot cope.

These drives would be well suited to work in servers, or where very high speeds and negligible drive latency are required.

Write in the comments if you have dealt with such drives. And do they have future prospects.