As we have already written in our reviews, the announcement of the GF104 graphics processor and GF104-based graphics cards (GeForce GTX 460 1 GB and 768 MB) marked the end of stagnation in the Nvidia camp. Prior to that release, Nvidia had only been competitive to AMD in the sector of expensive top-performance solutions which account for but a small share in both companies’ sales volumes. And even with the GF104 having already arrived, Nvidia still had some problems in one market sector. The company had filled in the entry-level segment (below $100) by means of DirectX 11-incompatible but competitive GT215, GT216 and GT218 chips, yet had only one card, the GeForce GTS 250, to fight back in the gap between the GeForce GT 240 (GT215) and GeForce GTX 460 (GF104).
The GeForce GTS 250 looked absolutely outdated in late 2010 as its G92 core traced its origin back to the G80 and actually belonged to the very first generation of Nvidia’s unified graphics architectures (originally released in late 2006). For comparison: the GeForce 400 series is a third generation while the GeForce GT 220/240 can be viewed as a second one with some reservations. Of course, we can praise the GeForce 8 architecture which has only exhausted itself by the end of 2010, yet such a market situation can only be considered as a company’s inability to match its opponent. While AMD had had already transitioned to DirectX 11 in every price segment, Nvidia had to fill in the gap in its product line-up with a graphics card which was not even DirectX 10.1 compliant. The GeForce GTS 250 called for a replacement, but the GF104 core was not a proper candidate both technically and economically. Nvidia had to develop another GPU which would be even simpler than the GF104, yet feature all the advantages of the Fermi architecture.
Nvidia was indeed busy developing such a GPU. September 13, they rolled out the GeForce GTS 450. This card is meant to replace the GeForce GTS 250 and make Nvidia technically competitive in the above-$100 sector. The new card is based on a new graphics chip which is codenamed GF106. It is simple, cheap to manufacture and powerful enough to be a full-featured member of the Fermi family and a worthy rival to the ATI Radeon HD 5700 series. Users of Nvidia products have long been waiting for such an affordable solution and we are going to discuss its highs and lows in this review. We will check out its power consumption and multimedia capabilities and see how well it stands against its predecessor and AMD’s alternatives.
Nvidia GeForce GTS 450: Architecture and Positioning
Despite its higher number, the GF106 chip is lower in the Fermi hierarchy than the earlier released GF104. Although it can be viewed as half the GF104 chip, it is quite complex in itself, incorporating as many as 1 billion transistors. Such complexity used to be a prerogative of top-end chips, e.g. the Nvidia G200, just a few years ago.
Representing the Fermi architecture, the GF106 is fully endowed with all its features such as high performance when processing geometrical data and doing tessellation. The GF106 is structurally alike to the GF104: the latter has two graphics processing clusters (GPCs) while the former, only one. But like in the GF104, the single cluster includes four multiprocessors. Each of these multiprocessors consists of 48 stream processors for a total of 192 ALUs and 32 TMUs. It is good that Nvidia did not cut the GF106 down like they did with the GF100 and GF104: the GF106 physically has 192 ALUs and 32 TMUs and all of them are active.
Well, there was a touch of a scalpel, though. Although the new GPU allows for three 64-bit memory controllers and 24 RBEs, the currently shipped version of GeForce GTS 450 comes with one of those subunits disabled. As a result, the new graphics card has 16 active RBEs and a 128-bit memory bus. The L2 cache has suffered accordingly. It is reduced from the physically present 384 to 256 kilobytes. We suppose Nvidia can release an improved version of the card and call it something like “GeForce GTS 455” as we have witnessed such examples in Nvidia’s history but currently the GF106 is only used in one graphics card model officially priced at $129. Here is how the GeForce HYS 450 compares with its relatives and competitors:
As we’ve said above, the GeForce GTS 450 is meant to replace the outdated GeForce GTS 250 which had the same recommended price of $129 at the time of its announcement. If we put these two models next to each other, we can easily see the fundamental trends in the world of gaming 3D graphics hardware for the PC platform: the newer solution is only half as strong as its predecessor in terms of texture mapping performance but superior in terms of computing resources and (this is not shown in the table) in geometry processing. The latter two factors are going to be crucial for current and next-generation games, yet the GF106 has the same bottleneck as its senior cousins while AMD’s Radeon HD 5 series has more advanced texture-mapping resources. The new GeForce GTS 460 looks good against the Radeon HD 5750 in terms of TMUs, but may find it difficult to compete with the Radeon HD 5770. Well, we won’t make any guesses now but we’ll just wait for the results of our practical tests. As for the frequencies, the GF106 seems to have higher frequency potential than the GF104 just because it is simpler, but the reference frequencies look somewhat odd. Nvidia could easily make them as pretty and round as 800/1600 MHz but did not do so for some unknown reason. We guess most GeForce GTS 450 cards will come to market with pre-overclocked frequencies, though.
The GF106 inherited the GF104’s full-featured support of multichannel HD audio formats (Dolby TrueHD and DTS-HD Master Audio) by implementing Protected Audio Path. Thus, Nvidia’s GPUs have caught up with the Radeon HD 5000 series in this respect. Nvidia specifies a TDP of 106 watts for its new solution, making it a rather poor choice for an economical HTPC. We will discuss the electric properties of the GeForce GTS 450 in more detail shortly.
The first GeForce GTS 450 to come to our test labs is a Zotac GeForce GTS 450 AMP!, so we will use it to test the new affordable solution from Nvidia.