We wrote earlier this month that Micron started sampling its GDDR5X memory and now a bit more technical details were revealed over at AnandTech. The first GDDR5X memory chips from Micron are named MT58K256M32JA, these chips feature 8Gb (1GB) capacity and are rated to run at 10Gbps, 11Gbps and 12Gbps bandwidth in quad data rate (QDR) with 16n prefetch. They use 1.35 V supply and I/O voltage as well as 1.8 V pump voltage (Vpp). The GDDR5X chips are made on a 20nm process, they feature a 32-bit interface and come in 190-ball BGA pacages with 14mm x 10mm dimensions.
The GDDR5X memory standard, as you might remember from our previous reports, is largely based on the GDDR5 specification, but has three crucial improvements: significantly higher data-rates (up to 14 Gb/s per pin with potential up to 16 Gb/s per pin), higher and more flexible chip capacities (4 Gb, 6 Gb, 8 Gb, 12 Gb and 16 Gb capacities are supported) and better energy efficiency thanks to lower supply and I/O voltage.
Thanks to the higher data rates of GDDR5X memory, video card makers will be able to increase the peak bandwidth of cards with a 256-bit memory bus to 320GB/s - 384GB/s, which previously required a more expensive and complicated 384-bit or 512-bit memory bus.
Micron started sampling its GDDR5X but this doesn't mean video cards with this memory will be available soon. The memory maker claims it won't be able to kick off mass production until this summer, which means the first video cards with GDDR5X are at least a half year away from us.