Workstation-Shootout: ATi FireGL V7600 vs. Nvidia Quadro FX 4600

A Balance Of Power This Fall?


The graphics card market for the workstation segment used to move at its own, more leisurely pace - until now. Although the rule still applies that cards aimed at the professional market space only appear a few months after their gaming/mainstream counterparts, ATI is speeding things up a bit this time. The Canadian company has released no fewer than five cards based on chips belonging to the R600 series, creating a numerical balance of power with Nvidia's product portfolio. After all, Nvidia's professional product line based on the G80 chip also counts five members, as the following table shows.

Workstation Cards with Shader Model 4.0 Chips
ATi cards based on the R600 series Nvidia cards based on the G80 series
FireGL V8650 (R600)
FireGL V8600 (R600)
FireGL V7600 (R600)
FireGL V5600 (RV630)
FireGL V3600 (RV630)
Quadro FX 5600 (G80)
Quadro FX 4600 (G80)
Quadro FX 1700 (G84)
Quadro FX 570 (G84)
Quadro FX 370 (G84)

In this article, we're comparing ATI's FireGL V7600 ($1000 plus taxes) to Nvidia's Quadro FX 4600 (€1650 including tax). For reference, we're also including the results of last year's models, the FireGL V7300 (R520) and Quadro FX 4500 (G70).

OpenGL Workstation Graphics - Market, Audience And Features
Looking at the workstation section of Nvidia's website, buyers will find a large variety of products. Aficionados will also discover several inconsistencies, though. For example, in some cases, the same product is associated with several market segments in the whitepapers. Additionally, the site lacks any information that would help differentiate between the current product line and last year's models - the model numbers alone give no indication of the what performance class the card actually belongs to.

While ATI's product naming scheme is not much more helpful or informative, it helps that the company's website differentiates between the 2006 and 2007 model years. While we don't want to get ahead of ourselves, we'll say at this point that buying the 2007 model is the better choice, regardless of what company you opt for.

To alleviate the problem of the confusing numbering scheme, and to help you tell the newcomers from last year's models, we have created the following table. Here, we attempt to group the cards into performance classes based on their real-world performance.

Performance Classification for professional Workstation Graphics Cards
Market Segment Nvidia ATi
Ultra-High-End Quadro FX 5600 FireGL V8600/V8650
High-End Quadro FX 4600 FireGL V7600
Mid-Range Quadro FX 1700 (FX 4500*) FireGL V5600 / (V7300*)
Entry-Level Quadro FX 570 / FX 370 (FX 1500*) FireGL V3600

Key: * Graphics chip from last year's generation

Before we get to the tests themselves, let's recap the genealogy of the workstation cards. From a hardware perspective, professional cards are not really separately developed products. Instead, they are derivatives of mainstream and gaming cards, making them almost identical to their non-professional counterparts. However, as you probably know, mainstream cards are a lot less expensive.

Now, the resourceful buyer may be tempted to simply choose the cheaper alternative, but the graphics companies take steps to prevent this, by making small changes to the workstation cards' BIOSes and graphics chips. The drivers are then written so that a mainstream card only delivers very meager performance in workstation tasks. Thus, only a Quadro or FireGL card can come close to its theoretical maximum performance in OpenGL.

Workstation Cards and their Mainstream/Gaming-Equivalents
Workstation Model Based on Chip Fab Process Mainstream Equivalent Video Memory
ATi FireGL V7600 R600 80 nm Radeon HD 2900 512 MB GDDR3
ATi FireGL V7300 R520 90 nm Radeon X1800 512 MB GDDR3
Nvidia Quadro FX 4600 G80 90 nm GeForce 8800 768 MB GDDR3
Nvidia Quadro FX 4500 G70 110 nm GeForce 7800 512 MB GDDR3

In the past, clock speeds were a relatively good indicator of performance, but today, you should focus more on the chip's technological details. With current cards, clock speed comparisons are only valid across the same chip generation - if you compare different generations, the numbers may quickly mislead you. One important criterion should be the shader model supported by the card. Our recommendation is to choose a card using shader model 4.0.

DirectX and OpenGL used to be competing APIs for software developers. Although OpenGL still dominates the workstation segment, DirectX is gaining more and more support as well. For example, 3D Studio Max 9.0 is a typical representative of workstation software. The application gives the user the choice between DirectX and OpenGL, but to achieve optimal shader performance, Tom's hardware recommends using DirectX in this case. Other software is increasingly using this API. Moreover, even the SPEC website includes DirectX results in the reference scores.

Important Features at a Glance
Workstation GPU Memory Bandwidth DirectX OpenGL Shader Model Core Clock Memory Clock Engine
ATi FireGL V7600 51.0 GB/s 10 2.1 4.0 500 MHz 510 MHz 320 SPUs
ATi FireGL V7300 41.6 GB/s 9.0c 2.0 3.0 600 MHz 650 MHz 16 P / 8 V
Nvidia Quadro FX 4600 67.2 GB/s 10 2.1 4.0 500 MHz 700 MHz 112 SPUs
Nvidia Quadro FX 4500 33.6 GB/s 9.0c 2.0 3.0 430 MHz 525 MHz 24 P / 8 V

Key: SPUs = Stream Processing Units, P = Pixel Shader, V = Vertex Shader

ATI sends its workstation lineup into the market with bold claims. According to a press release, the new R600-based product line is meant to offer a 300% performance advantage over previous models. Of course, such claims will net the company the desired attention, but at the same time, they also inspire a certain level of skepticism: our first reaction was that ATI was confusing marketing with hyperbole. Nonetheless, if there is even a kernel of truth to these claims, the new cards must have a lot to offer that would be worth examining more closely.

In this comparison, we are limiting ourselves to the FireGL V7600, which comes with 512 MB of video memory and sells for a recommended price of $1000. ATI positions it in the high-end segment for CAD and DCC applications. Within the workstation family, it has two bigger siblings, namely the V8650 with 2 GB of memory and the V8600 with 1 GB. These two models are a good deal more expensive, and can only unleash their full potential in applications using massive textures and huge models or scenes. On the lower end, there are also two pared down versions: these are the V5600 with 512 MB of video RAM, and the V3600 with a meager 256 MB.

We are happy to report that all of ATI's cards finally sport two dual-link capable DVI video outputs, enabling the use of large wide-screen monitors. Each display can now have a maximum of 2560x1600 pixels, for a grand total of 5020 pixels across.

In its whitepapers, ATI deliberately avoids the use of the term "CrossFire", which hails from the mainstream segment. Instead, the company soberly speaks of "multiple card support". In plain English, the principle is the same, allowing two to four cards to be used in parallel to increase the processing performance. Nvidia calls its implementation of this technique "SLI".

Compared to the previous generation, the GPU architecture has fundamentally changed. For instance, with the new generation, separate pixel and vertex shaders are a thing of the past, and have been replaced by so-called "unified shaders". The advantage of this approach is that shader resources can be dynamically allocated depending on the application's current needs. If the task has a lot of geometry computations, the vertex shader capacity is increased, while the pixel shader power is upped for rendering tasks. This process is fully automatic.

One feature is especially interesting for medical applications such as X-rays / radiology. The display engine is able to handle 10 bits per color component (R, G and B), or well over one billion colors. The same goes for the black/white channel (think X-ray images), which supports up to 210 = 1024 shades of grey, rather than the standard 256.



8-pin Molex connector for auxiliary power on the FireGL V7600


V7600 Crossfire connector for use with two cards running in tandem.