Industry sources revealed to TechPowerUp some pretty interesting specifications of AMD's two upcoming GPUs based on the 4th generation Graphics CoreNext "Polaris" architecture. The company is preparing a performance-segment GPU and a mainstream one. It turns out, that the performance-segment chip, which the press has been referring to as "Ellesmere," could feature 32 compute units (CUs), and not the previously thought 40.

Assuming that each CU continues to consist of 64 stream processors (SP), you're looking at an SP count of 2,048. What's more, this chip is said to offer a single-precision floating point performance of 5.5 TFLOP/s, as claimed by AMD. To put this into perspective, the company had claimed 5.2 TFLOP/s for the "Hawaii"/"Grenada" based FirePro W9100, which launched earlier this February, and that SKU featured all 2,816 SP present on the chip. So this chip is definitely faster than most "Hawaii" based SKUs.

AMD is reportedly giving final touches to the Radeon R7 370X, to preempt launch of NVIDIA GeForce GTX 950. The card will be based on the "Trinidad XT" silicon, and will max out components physically present on the chip. This means that the card will feature 1,280 Graphics CoreNext stream processors, 80 TMUs, 32 ROPs, and a 256-bit wide GDDR5 memory interface, holding 2 GB or 4 GB of memory. Leaked screenshots that disclose these specs suggest that AMD will carry over clock speeds from the R9 270X, working out to 1180 MHz core, and 5.60 GHz (GDDR5-effective) memory, working out to a memory bandwidth of 179.2 GB/s.

It looks like AMD's desktop discrete GPU lineup for 2015 will see a mix of rebrands, re-codename, and one big new chip, all making up the new Radeon R7 300 and R9 300 series. Cards based in this lineup should begin rolling out this month. Leaks from OEMs such as this one, suggest that the first of these should begin rolling out as early as June 16.

The spread is pretty cut and dry. "Hawaii," the chip driving the R9 290 series, will not only get a new codename as "Grenada," but also a seamless rebrand to the R9 390 series, with Grenada Pro making up the R9 390, and Grenada XT making up the R9 390X. One possibility could be AMD taking advantage of low 4 Gbit GDDR5 chip prices to cram 8 GB of standard memory amount, across Grenada's 512-bit wide memory interface. The R9 390X will compete with the GeForce GTX 970, while the R9 390 will offer an option in the vast price and performance gorge between the GTX 960 and GTX 970.