Memory speed tiers/LPDDR5X/LPDDR5X-7500
LPDDR5X-7500 bandwidth
LPDDR5X-7500 transfers data 7,500 million times a second on every bit of the bus. On a 128-bit bus that is a theoretical peak of 120 GB/s.
Theoretical peak, by bus width
| Bus width | Theoretical peak | Arithmetic |
|---|---|---|
| 64-bit | 60 GB/s | 7,500 MT/s x 64 bits / 8 / 1000 = 60 GB/s |
| 128-bit | 120 GB/s | 7,500 MT/s x 128 bits / 8 / 1000 = 120 GB/s |
| 256-bit | 240 GB/s | 7,500 MT/s x 256 bits / 8 / 1000 = 240 GB/s |
LPDDR5X is soldered beside the processor in 16-bit channels, and the processor sets how many there are. The total width is a property of the laptop's processor, not of the memory.
The peak is arithmetic, not a measurement: the data rate times the bus width, divided by 8 bits per byte and by 1,000. Memory never delivers all of it. Refresh cycles, switching between rows and the traffic of every other core take a share, so a measured figure below the peak is expected and is not a fault.
The RAM speed test measures the bandwidth your machine delivers from the browser, from one thread and from all of them. Read that figure against the row above that matches your bus: one module or channel is 64-bit, two in dual channel are 128-bit.
The next speed down and up