ASUS GTX 750 Ti OC 2 GB Review

Name: ASUS GTX 750 Ti OC 2 GB
Brand: ASUS

W1zzard

on Feb 20th, 2014,

in Graphics Cards.

Manufacturer: ASUS

(21 Comments) »

Introduction

Here it is, NVIDIA's GeForce GTX 750 Ti, one of the first GPUs based on its next-generation "Maxwell" GPU architecture. First reports of the chip being based on "Maxwell" hit us by surprise as we presumed that a new micro-architecture is invariably pegged to NVIDIA's foundry partner, TSMC, to launch its next-generation 20 nanometer silicon fabrication process. The fact that TSMC's 20 nm node isn't in a position to ship out such complex ASICs as graphics processors right now and that NVIDIA wouldn't want its new architecture to in any way be hit by unforeseen issues arising out of the move to a new process may have led to the decision to use the existing 28 nanometer process.

The GeForce GTX 750 Ti and GTX 750 (also launched today) are based on the 28 nm GM107 (GeForce-Maxwell 107) silicon. This 1.87 billion-transistor GPU features a basic component hierarchy that's not too different from that of "Kepler," but sees some under-the-hood changes in the design of its key parallel processing sub-unit, the streaming multiprocessor "Maxwell" (SMM). The GTX 750 Ti is positioned between the GTX 760 and GTX 660, which is a sizable gap to fill. NVIDIA is promising some huge performance-per-watt gains with "Maxwell." Given that the GM107 is based on the same 28 nm process as the GeForce Kepler series, there's only one way NVIDIA can deliver on its promise - by developing a better overall architecture.

Today we are reviewing the ASUS GTX 750 Ti OC. This will be our first review of a GTX 750 Ti with a 6-pin power connector.

ASUS has also overclocked the card out of the box and uses their DirectCU dual-fan thermal solution on the card, but without heatpipes.

The card is currently available online for $160, which is a $10 price premium over the reference design.

ASUS GTX 750 Ti Market Segment Analysis
	GeForce GTX 650 Ti	Radeon HD 7790	Radeon HD 7850	GeForce GTX 750	Radeon R7 260X	GTX 650 Ti Boost	GeForce GTX 750 Ti	ASUS GTX 750 Ti OC	Radeon R7 265	GeForce GTX 660	Radeon HD 7870	Radeon R9 270X	GeForce GTX 660 Ti	GeForce GTX 760
Shader Units	768	896	1024	512	896	768	640	640	1024	960	1280	1280	1344	1152
ROPs	16	16	32	16	16	24	16	16	32	24	32	32	24	32
Graphics Processor	GK106	Bonaire	Pitcairn	GM107	Bonaire	GK106	GM107	GM107	Pitcairn	GK106	Pitcairn	Pitcairn	GK104	GK104
Transistors	2540M	2080M	2800M	1870M	2080M	2540M	1870M	1870M	2800M	2540M	2800M	2800M	3500M	3500M
Memory Size	1024 MB	1024 MB	2048 MB	1024 MB	2048 MB	2048 MB	2048 MB	2048 MB	2048 MB	2048 MB	2048 MB	2048 MB	2048 MB	2048 MB
Memory Bus Width	128 bit	128 bit	256 bit	128 bit	128 bit	192 bit	128 bit	128 bit	256 bit	192 bit	256 bit	256 bit	192 bit	256 bit
Core Clock	925 MHz	1000 MHz	860 MHz	1020 MHz+	1100 MHz	980 MHz+	1020 MHz+	1072 MHz+	925 MHz	980 MHz+	1000 MHz	1050 MHz	915 MHz+	980 MHz+
Memory Clock	1350 MHz	1500 MHz	1200 MHz	1250 MHz	1625 MHz	1502 MHz	1350 MHz	1350 MHz	1400 MHz	1502 MHz	1200 MHz	1400 MHz	1502 MHz	1502 MHz
Price	$100	$115	$150	$120	$130	$130	$150	$160	$150	$190	$190	$200	$260	$240

Architecture

NVIDIA's primary design goal with the GM107 is to up the performance-per-watt game. If NVIDIA achieves a significant performance-per-watt gain with "Maxwell" over "Kepler," it can trade that gain for performance on bigger "Maxwell" chips bolstered by the 20 nm process. It's this fact that makes the GK107 academically interesting.

As we mentioned earlier, the GM107 essentially features the same component hierarchy as previous generation "Kepler" GPUs, but introduces changes to the design of the streaming multiprocessor (SMM), the parallel-processing sub-unit of the GPU. At its outermost ring, the GM107 features the GigaThread Engine, a component that marshals data and instructions between the graphics processing cluster (GPC), the raster operations processors (ROPs), the L3 cache, the memory controllers, the bus interface, and the display I/O.

Several GPCs can typically be routed to a GigaThread engine, but being a mid-range GPU, the GM107 features just one. This GPC features a raster engine that handles high-level assembly of data and instructions and five streaming multiprocessors (SMMs), which is where the number crunching takes place. Unlike the streaming multiprocessors (SMXs) of "Kepler" GPUs, which feature an incoherent group of 192 CUDA cores, the SMM features four groups of 32 cores each, which totals 128 per SMM. The SMM shares a Polymorph Engine that features components such as the tessellator, fetch, setup, transform, and stream output with the four groups. The four groups of 32 CUDA cores, each, feature dedicated warp schedulers and registers, with a texture cache cushioning transfers between the groups and TMUs. The GM107 hence features a total of 640 CUDA cores and 48 TMUs. At a higher level, the chip features 16 color ROPs and a 128-bit wide GDDR5 memory interface.