Samsung Electronics just announced that the company’s GDDR7 memory modules will use pulse amplitude modulation (PAM3) signals, with 25 percent more power efficiency and the same percentage over the non-return-to-zero signal (NRZ) used in GDDR6 memory.
Samsung officially confirms the PAM3 signal for GDDR7 memory, showing a more significant improvement over NRZ and PAM4 by 25%
Last year, Intel CEO Gregory M. Bryant traveled to Intel’s Israeli R&D facilities and posted photos of his trip to Twitter. During the visit, Bryant accidentally leaked an image showing information about the yet-to-be-released Thunderbolt 5 technology. Once the executive realized his mistake, the image was removed from the post but described some related developments, namely the PAM3 (GDDR7) signal.
to summarise, Turn on PAM3 signals GDDR7 is the way a system generates zeros and ones on a single bit. When the tweet was posted, the industry standard was PAM4 and NRZ. Numbers three and four are number zero and one variants (00, 01, 10 and 11) that go into NRZ and PAM4. In PAM 3 signals, the numerical values are divided between negative, positive, and zero values (-1, 0, and +1). At that time, PAM3 memory technology was more efficient than PAM4 but lower than NRZ. This has now changed, and PAM3 will be the new standard.
Samsung continued to confirm that the bandwidth supported by the new GDDR7 memory will operate at a transfer rate of 36Gbps. Compared to AMD Radeon RX 6000 series graphics cards, the bandwidth is now twice as fast as the chipsets used in the GPU series, which used to top out at 18Gbps. The new GDDR7 is also faster than the AMD Radeon 7000 series GPU.
There are currently no product versions that will use Samsung GDDR7 memory modules, and Samsung Electronics has not yet disclosed dates for its implementation in graphics cards. However, we should expect that the new standard will produce 1152GB/s of memory bandwidth over a 256-bit memory bus, while when used with 384-bit memory controllers it will produce 1728GB/s. Samsung also recently announced its GDDR6W memory which has twice the capacity and channels versus GDDR6.
News sources: VideoCardz, Dr. Ian Cutters on TwitterAnandtech, TechPowerUP