The snapshot shows that the die surface of the R580 is somewhat larger than the R520, and the former is a square whereas the latter is a rectangle. The R580 in its turn is smaller than the less complex NVIDIA G70 chip thanks to 0.09-micron tech process.
Such a small area increase is explained by the rather small increase in the amount of transistors, from 321 to 384 million. The R580 has 48 pixel shader processors on board as opposed to the R520’s 16 and it means the pixel processors don’t require too many transistors. Easy to calculate, 48 pixel processors are comprised of less than 90 million transistors – a quarter of the total amount. The rest of the transistors make up the caches, texture units, ring-bus memory controller, ultra-threading dispatch processor, etc.
As for the marking, the text “ENG SAMPLE” speaks for itself – this is an engineering sample of the R580 chip. It is dated the 45th week of the last year, i.e. early November. ATI Technologies said they had received the first batch of commercial wafers from TSMC at the end of November and that they already had working samples of the R580 even before the official announcement of its predecessor, RADEON X1800 (R520).
The GPU die is protected against damage with a traditional metal frame. Since we are dealing with a RADEON X1900 XT, the graphics processor is clocked at the same frequency as on the RADEON X1800 XT, i.e. at 625MHz. The graphics core frequency of the RADEON X1900 XTX is 650MHz.
Like the RADEON X1800 XT, the RADEON X1900 XT CrossFire Edition uses Samsung K4J52324QC-BJ12 GDDR3 memory. These chips are 512Mbit each, so eight such chips suffice for a total of 512MB of graphics memory with 256-bit access. The access time of the chips is 1.25 nanoseconds; they are rated to work at 2.0V voltage and at 800 (1600) MHz frequency. The memory of the RADEON X1900 XT works at a lower frequency than on the RADEON X1800 XT: 725 (1450) MHz against 750 (1500) MHz.
The memory frequency of the higher-performing RADEON X1900 XTX is 775 (1550) MHz and Samsung’s 1.1ns K4J52324QC-BJ11 chips are employed. These chips can theoretically be clocked at 1800MHz, but ATI decided to keep to more conservative settings. It is quite possible that ATI’s partners will come up with “updated” versions of RADEON X1900 XTX with higher chip/memory frequency at some moment in the future. Such graphics cards may appear along with the G71 chip (GeForce 7900), an updated version of the G70 processor, or earlier as “extreme” versions of the card.
The cooling system of the RADEON X1900 XT/XTX is the same as the RADEON X1900 XT’s: a blower is pumping air from inside the PC case and into the thin-ribbed copper heatsink with a massive sole and is then exhausting it to the outside. The heatsink contacts the GPU die through a layer of dark-gray thermal paste; the memory chips give their heat away to the cooler’s aluminum sole via elastic rubber-like thermal pads. This cooling system is quite efficient and quiet even at the lowest speed of the fan. When the fan speed increases, the card becomes noticeably louder, the plastic casing acting as a resonator.