Stefan Mileschin

AMD's upcoming Radeon R9 390X and R9 390 performance-segment graphics cards reportedly feature higher GPU and memory clocks over the products they are a re-branding of, the R9 290X and R9 290, respectively. The 28 nm "Grenada" silicon they are based on, is identical to "Hawaii," down to the last transistor. This has been confirmed by leaked GPU-Z screenshots, which reveal the device-IDs of the two cards to be identical to those of the R9 290X and R9 290. Since the Device-IDs are the same, GPU-Z is reading the chip as "Hawaii." The code-name "Grenada" appears in the BIOS version string.

Unlike older, more blatant re-brands, such as GeForce 8800 GT to 9800 GT, AMD did drop in a few changes. To begin with, the memory amount has been doubled on both cards, to 8 GB. The memory clock has been increased from 1250 MHz (5.00 GHz GDDR5-effective), to 1500 MHz (6.00 GDDR5-effective), resulting in memory bandwidth increase to 384 GB/s, up from 320 GB/s. The core clock speed on the R9 390X is 1050 MHz (up from 1000 MHz on R9 290X); and 1000 MHz on the R9 390 (up from 947 MHz on the R9 290).

http://www.techpowerup.com/213464/ra...decessors.html