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.

Sapphire unveiled its highest tuning air-cooled TOXIC variant for the Radeon R9 390. Targeted at the Greater China region (PRC, Hong Kong, Taiwan), this card features a swanky new VaporX vapor-chamber cooling solution, and the highest factory-overclock by the company for this chip. The core is clocked at 1120 MHz against reference clocks of 1000 MHz, and an untouched 6.00 GHz (GDDR5-effective) memory clock.

The cooling solution consists of a large vapor-chamber plate, from which a number of 8 mm-thick copper heat pipes convey heat to two aluminium fin stacks, which are ventilated by three 100 mm spinners. A chunky, ridged, aluminium base-plate covers nearly every other part of the PCB, cooling the VRM and memory chips. Based on the 28 nm "Grenada" silicon, the R9 390 features 2,560 stream processors, 160 TMUs, 64 ROPs, and a 512-bit wide GDDR5 memory interface, holding 8 GB of memory.

ASUS managed to tame AMD's feisty "Grenada" silicon, which powers the Radeon R9 390 and Radeon R9 390X, by announcing two high-end graphics cards based on its new triple-fan STRIX DirectCU 3 cooling solution. The cooler turns its fans off when the GPU is idling (common desktop / light-3D loads), and begins to spool up only under heavy 3D loads. The company claims that this will be the quietest R9 390 series cards you can buy.

The STRIX DirectCU 3 cooler is the same as the one pictured cooling the GeForce GTX 980 Ti STRIX, which we spotted at Computex. It features a huge monolithic aluminium fin-stack heatsink, to which heat drawn from the GPU is fed by four 10 mm thick nickel-plated copper heat pipes. This heatsink is ventilated by three 100 mm spinners. This heatsink has contact bases even over the card's 8-phase VRM, and a base-plate that draws heat from its 16 GDDR5 memory chips, that make up 8 GB. The R9 390 STRIX offers factory OC of 1050 MHz (vs. 1000 MHz reference); while the R9 390X STRIX offers 1070 MHz (vs. 1050 MHz reference). The memory ticks at 6.00 GHz on both cards. ASUS didn't announce pricing.

AMD wrapped up today's GPU launch marathon, with the Radeon R9 390 series; which includes the R9 390, and the R9 390X. The Radeon R9 390 is priced at US $329, and offers performance competitive to the GeForce GTX 970. The R9 390X, on the other hand, is starts at US $429, and offers performance that's between the GTX 970 and GTX 980, while being closer to the latter. Both are based on the 28 nm "Grenada" silicon, which is the "Hawaii" silicon re-hashed.

The R9 390 packs 2,560 stream processors, 160 TMUs, 64 ROPs; while the R9 390X offers 2,816 stream processors, 176 TMUs, and 64 ROPs. Both cards offer 8 GB of GDDR5 memory, across the chips' 512-bit wide memory interfaces. Both cards let you game at 1440p with settings maxed out; or 4K Ultra HD, with reasonably high eye-candy. The R9 390 features core clock speeds of 1000 MHz, while the R9 390X tops that with 1050 MHz core. The memory on both cards, is clocked at 6.00 GHz (GDDR5-effective), translating into a staggering 384 GB/s memory bandwidth.

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).

People with access to an XFX Radeon R9 390X graphics card, took it apart to take a peek at its PCB. What they uncovered comes as no surprise - the underlying PCB is identical in design to AMD reference PCB for the Radeon R9 290X, down the location of every tiny SMT component. At best, the brands on the chokes and bigger conductive polymer caps differ; and 512 Gbit GDDR5 chips under the heatspreader, making up 8 GB of the standard memory amount. The GPU itself, codenamed "Grenada," looks identical to the "Hawaii" silicon which drove the R9 290 series. It's highly unlikely that it features updated Graphics CoreNext 1.2 stream processors, as older rumors suggested.

Ahead of its possible June 16 launch, more pictures of AIB-branded Radeon R9 390X graphics cards are hitting the wires. Here, we have an XFX-branded R9 390X, complete with its box-art. The R9 390X, is expected to be a re-brand of the previous generation R9 290X, with its standard memory amount raised to 8 GB. It's based on the 28 nm "Grenada" silicon. We've seen no evidence pointing at "Grenada" being some sort of an upgrade of "Hawaii" with newer GCN 1.2 stream processors. Perhaps AMD polished its electricals to the extent it could, without changing the silicon. We'll know for sure only next week.

XFX' Radeon R9 390X features a custom air cooling solution, which is taller than the one the company used on its R9 290 series products. It still retains its 2-slot form. The cooler consists of two aluminium fin-stacks, along the edges of seven 8 mm thick copper heat pipes, which draw heat from the GPU at the base. A metal heatspreader conveys heat from the memory chips to the main heatsink; while individual metal heatsinks cool the VRM. The card draws power from a combination of 6-pin and 8-pin PCIe power connectors. Display outputs include two dual-link DVI, and one each of HDMI 1.4a and DisplayPort 1.2a connectors.

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.

Earlier this day, HP announced its newest line of desktop PCs, one of which comes with a curious-sounding Radeon R9 380 graphics card. HP's product pages for its new desktops aren't active, yet, leaving us to only speculate on what the R9 380 could be. One theory making rounds says that the R9 380 could either be a re-branded R9 285, or be based on its "Tonga" silicon, which physically features 2,048 stream processors based on Graphics CoreNext (GCN) 1.2 architecture, and a 384-bit wide GDDR5 memory interface. Another theory states that the R9 380 could be an OEM-only re-brand of the R9 280 or R9 280X, based on the 3+ year old "Tahiti" silicon.

The former theory sounds more plausible, because re-branding a "Tahiti" based product would be suicidal for AMD. Although based on GCN, "Tahiti" lacks a lot of architecture features introduced with "Hawaii" and "Tonga." AMD practically stopped optimizing games for "Tahiti," and some of its new features, such as FreeSync and XDMA CrossFire, can't be implemented on it. "Tonga," on the other hand, supports both these features, and one can create an SKU with all its 2,048 stream processors, and its full 384-bit GDDR5 memory interface unlocked. If the R9 380 is indeed an OEM-only product, then it's likely that the company's retail-channel products could be branded in the succeeding R9 400 series. GPU makers tend to re-brand and bump their SKUs by a series for OEMs to peddle in their "new" products at short notice.

AMD's upcoming Radeon R9 380X and R9 380 graphics cards, with which it wants to immediately address the GTX 980 and GTX 970, will be based on a "new" silicon codenamed "Grenada." Built on the 28 nm silicon fab process, Grenada will be a refined variant of "Hawaii," much in the same way as "Curacao" was of "Pitcairn," in the previous generation.

The Grenada silicon will have the same specs as Hawaii - 2,816 GCN stream processors, 176 TMUs, 64 ROPs, and a 512-bit wide GDDR5 memory interface, holding 4 GB memory. Refinements in the silicon over Hawaii could allow AMD to increase clock speeds, to outperform the GTX 980 and GTX 970. We don't expect the chip to be any more energy efficient at its final clocks, than Hawaii. AMD's design focus appears to be performance. AMD could save itself the embarrassment of a loud reference design cooler, by throwing the chip up for quiet custom-design cooling solutions from AIB (add-in board) partners from day-one.