Side-by-Side Comparison
Graphics Cards
GDDR6X vs. PCIe
Comparing 2 standards across 10 specifications. 10 key differences identified.
Comparing:
GDDR6X
PCIe
GDDR6X is not a JEDEC standard -- it's a proprietary memory technology Micron developed specifically in collaboration with Nvidia, first shipping in 2020 with the RTX 3080 and RTX 3090. It uses PAM4 signaling, the same two-bit-per-symbol approach PCIe 6.0 later adopted, to reach 19-21 Gbit/s per pin.
PCIe is the interface standard graphics cards connect through, typically using all 16 lanes of a slot for maximum bandwidth. Each generation has roughly doubled per-lane throughput since 2003, from PCIe 1.0's 250 MB/s per lane to PCIe 6.0's 7.56 GB/s per lane using a new PAM4 signaling scheme.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard
|
Proprietary (Micron, developed with Nvidia) -- not JEDEC | — |
|
Signaling
|
PAM4 (2 bits per symbol, vs. GDDR5/6's 1-bit NRZ) | — |
|
Max Bandwidth / Data Rate
|
19–21 Gbit/s per pin | — |
|
Introduced
|
2020 (Nvidia RTX 3080 and RTX 3090) | — |
|
PCIe 1.0 (2003)
|
— | 0.25 GB/s/lane | 4 GB/s x16 |
|
PCIe 2.0 (2007)
|
— | 0.5 GB/s/lane | 8 GB/s x16 |
|
PCIe 3.0 (2010)
|
— | 0.985 GB/s/lane | 15.75 GB/s x16 |
|
PCIe 4.0 (2017)
|
— | 1.969 GB/s/lane | 31.51 GB/s x16 |
|
PCIe 5.0 (2019)
|
— | 3.938 GB/s/lane | 63.02 GB/s x16 |
|
PCIe 6.0 (2022 spec)
|
— | 7.563 GB/s/lane | 121 GB/s x16 |