Introduction

The Sapphire Radeon X1950 GT card

Last Fall ATI reinvigorated their mainstream graphics lineup, introducing a slew of new graphics processors at both the high and low ends of the mainstream segment. The GPU that garnered the most attention among enthusiasts was easily the Radeon X1950 Pro though.

With its brand new RV570 graphics core, the X1950 Pro turned heads. The chip was equipped with 36 pixel shaders -- just 12 shading units shy of ATI’s flagship Radeon X1950 XTX -- and also sported a 256-bit external memory interface. Arguably the Radeon X1950 Pro’s most notable new feature though was its integrated CrossFire engine. Whereas previous Radeon cards relied on an array of external chips to provide CrossFire functionality, the Radeon X1950 Pro was the first ATI card offered with integrated CrossFire built-in to every card. This ended the need for separate CrossFire master cards that could sometimes be hard to find at retail, and the thick, ungainly CrossFire dongles that accompanied them.



Priced then at an MSRP of $199, the Radeon X1950 Pro was well received among enthusiasts. We called it a worthy successor to the Radeon X1900 GT in our X1950 Pro Performance Preview article, with the Radeon X1950 Pro often outperforming its closest competitor, the GeForce 7900 GS in many benchmarks.

Over time though prices on the GeForce 7900 GS slowly began to fall and rather than reduce prices on the Radeon X1950 GT accordingly, ATI instead decided to introduce another graphics card based on the RV570 GPU family – the Radeon X1950 GT, which was announced at the end of last month. Sapphire’s Radeon X1950 GT is the first X1950 GT card to hit US shores, and it’s the card we’re looking at today. However, first let’s go over the Radeon X1950 GT GPU at the heart of Sapphire’s latest mainstream card.

Size comparison: Sapphire X1950 GT and GeForce 7900 GT reference board

The X1950 Pro reference board and Sapphire X1950 GT

The innards of the Radeon X1950 GT

At the heart of the Radeon X1950 GT is the same RV570 GPU used in the Radeon X1950 Pro. If you recall, RV570 is built on TSMC’s 80-nm manufacturing process and contains 36 pixel shaders, 8 vertex shaders, 12 TMUs and 12 ROPs. Keeping the graphics core fed with data are eight 32-bit memory controllers, for a 256-bit memory interface.

All of this carries over unchanged in the Radeon X1950 GT, none of the shaders are deactivated. Instead AMD has lowered the clock speeds of the graphics core and memory: whereas the X1950 Pro ran at 575MHz, the Radeon X1950 GT runs at an even 500MHz. The speed of the board’s memory is also reduced, running at 600MHz (versus 690MHz on the Radeon X1950 Pro).

Long fan cable huh?

The Sapphire X1950 GT is considerably longer than the 7900 GT from NVIDIA

2xDual-link DVIs w/HDCP

The following chart summarizes how AMD’s newest mainstream GPU stacks up to previous offerings and the NVIDIA GeForce 7900 GS it competes with:

Mainstream GPU Comparison
	GPU	Die Size	Core Clock Speed	Pixel Shaders	Vertex Shaders	ROPs	Texel Fill-rate	Memory Speed	Memory Bandwidth	MSRP
Radeon X1950 GT	RV570	230.5	500	36	8	12	6000	1200	38.4	$179
Radeon X1900 GT (original)	R580	315	575	36	8	12	6900	1200	38.4	EOL
Radeon X1900 GT (revised)	R580	315	512	36	8	12	6144	1314	42	EOL
Radeon X1950 Pro	RV570	230.5	575	36	8	12	6900	1380	44.2	$199
GeForce 7900 GS	G71	196	450	20	7	16	9000	1320	42.2	$179-$199

As you can see in the chart above, due to its slower graphics core, the Radeon X1950 GT will run a little slower than the original Radeon X1900 GT, although thanks to its new RV570 graphics core, the Radeon X1950 GT has the added feature of native CrossFire support and HDCP. Apparently under the new AMD-ATI you have to give up a little to get a little (in return), at least as far as the Radeon X1950 GT is concerned.