Product Review: AMD Radeon Pro W6400 GPU for Workstations

WHEN WE REVIEWED AMD’s new Radeon Pro W6600, the big sister to this new Radeon Pro W6400 GPU, we made note that the W6600 was partly aimed squarely at the architecture side of the AEC market. This latest GPU is aimed at a wider professional audience that includes both AEC and manufacturing design professionals as well as a wider business-class audience that also needs accelerated performance across a range of post-Covid “new normal” business functions like video chat communications.

Economics

AMD’s latest professional GPU is well-timed for a challenging economic context. After two years in pandemic survival mode, many businesses are seeing exploding demand yet struggling to find qualified talent. The net result means firms must be even smarter today about their information technology budgets as salaries and sign-on bonuses rise.

From this view, AMD’s Radeon Pro W6400 delivers a valuable option, offering the pro-market the most affordable GPU with capacity for real-time, hardware-accelerated raytracing graphics. Like its AMD RDNA 2 Architecture big siblings, the new GPU taps the excellent Radeon Pro Software for graphics management, performance tuning, recording, monitoring, and more. It also supports Viewport Boost technology to accelerate real-time raytracing in applications like Twinmotion and Revit, for example.

 

With a 229 USD MSRP, the W6400 also delivers excellent performance per dollar metrics for a wide range of dominant CAD industry workflows. This is especially true for AEC users working with small to medium-sized models in SketchUp and leading BIM applications, as well as MCAD users working in average-sized models and assemblies predominantly in OpenGL viewports rendered with shaded with edges with and without anti-aliasing. (see our test results section below).

The Raytracing Value Proposition

Most AEC and MCAD users face tight deadlines and tend to optimize their software tools to allow for the fastest workflows. There is considerable pressure (and need) for knowledge about optimizing viewport responsiveness across nearly all CAD/BIM tools. That issue isn’t going away.

Now combined with that pressing demand is the reality that real-time raytracing is truly here and is transforming workflows in both AEC and MCAD. In AEC, it means that architects can loop in views of their building designs with much more realistic raytraced shadows and lighting as part of their iterative design workflow.

The industry is also moving (though it will move slowly according to a Tech Soft 3D executive we recently spoke to) from older generation graphics engines like OpenGL to the utilization of more modern, low-level APIs like Vulkan and Metal, and DirectX 12. As CAD and BIM developers modernize their software’s graphics pipeline, real-time raytracing is beginning to factor into future workflow options.

Autodesk is working on its One Graphics system, Dassault Systèmes has Project Romulan, the Nemetschek Group in the near future will proliferate its Redshift Renderer throughout its daughter companies’ digital tools, and Tech Soft 3D has a new partnership with Chaos. From this perspective, AMD’s entry-level workstation GPU gets included (not excluded) in future innovations with rendering engines that will leverage real-time raytracing in the viewport. This should give buyers some assurance.

AMD Radeon Pro W6400

The newest AMD RDNA 2 Architecture workstation GPU is built on a 6nm process node, features 16 MB AMD Infinity Cache (L3), and 4 GB of high-performance GDDR6 memory.

Like its big sister GPUs (W6600, W6800, etc), it features hardware-accelerated raytracing, in this case via 12 Ray Accelerators. Importantly, this newest Radeon Pro GPU is also VR-ready (more on tests below) and supports AMD’s unique Viewport Boost technology useful for apps like Revit and Twinmotion. Other key details include:

• 768 Stream Processors
• PCI Express 4.0 Support for Advanced Data Transfer
• DirectX 12, OpenGL 4.6, OpenCL 2.2, Vulkan 1.2
• 4GB GDDR6 memory with 128-bit memory interface width
• 128 GB/s peak memory bandwidth
• 2 x DisplayPort 1.4
• 7680 x 4320 Max resolution
• 50 watts (Peak Power) / no connectors
• Single-Slot, Half Height, 6.6″ length (SFF capable)

The AMD Radeon Pro W6400 sustains 3.54 Peak Teraflops (FP32), compared to AMD’s Radeon Pro W6600 at 10.4 Peak Teraflops, the bigger sister GPU we do a lot of benchmark comparisons to in this article. The GPU with its 5.4 billion transistors has OS support for Windows 10, 11, and Linux.

Business Apps

Before we jump into our CAD/BIM/3D testing benchmarks, a quick note about the W6400 is in order. AMD sees this GPU as an excellent solution for SFF and entry-level workstations directed at mixed business loads, across various industries, not just those industry segments connected to the CAD markets.

AMD also sees the Radeon Pro W6400 as an excellent upgrade choice for existing workstation owners using similar-sized SFF based GPUs or as a better option than NVIDIA’s similarly priced T600, a GPU that does not support real-time raytracing at the hardware level. It is also half the price of NVIDA’s newest SFF pro-GPU the RTX A2000, a graphics card that performs similarly to AMD’s W6600 we reviewed recently.

In comparison to the NVIDIA T600, the W6400 performs anywhere from 4 percent to about 63 percent faster at a range of tasks. It is particularly faster at photo editing (63 percent) and rendering and visualization (42 percent), based on AMD’s own benchmarking.

next page: Benchmarking and Performance Results

Benchmarking and Performance Results

We will cover our benchmarking first and then go to real-world application testing. Like prior reviews, we have utilized SketchUp as not just a very popular design modeling tool in AEC, but also as a proxy for OpenGL-based BIM applications, or OpenGL shaded with edges-based viewport rendering with or without anti-aliasing. We also ran Creo and Solidworks subtests as part of SPECviewperf 2020. Here are the tests and benchmarks we go through:

• CompuBench — OpenCL (download link)
• GFXbench — OpenGL only test(s) (download link)
• VRMark — virtual reality benchmark (download link)
• SPECviewperf 2020 V3 (selected OpenGL CAD tests) — (download link)
• SketchUp TTD FPS — OpenGL 3.1 based FPS tests using our own test files

We also gave Twinmotion a spin using the same file we have used in our last two prior GPU tests. (see the third page in this report).

Summary Conclusions

AMD’s Radeon Pro W6400 is fundamentally intended for three groups of users: (1) mainstream modern business users who benefit from GPU performance in apps like video conferencing, photo-editing, and marketing applications rich in graphic media, including video, (2) 2D CAD designers and engineers, and (3) budget-conscious professionals in need of workstation-class GPUs.

What we are focused on are these last two groups. Those who do medium to extreme 3D CAD workloads are going to be better served by AMD’s Radeon Pro W6600. But when we write “better” it needs qualifications. In the AEC space, BIM and 3D modeling workloads in OpenGL with shaded, shaded + edges, with and without anti-aliasing, are actually economically better served by the W6400 than the W6600 on a performance per dollar basis. This includes MCAD users working in tools like PTC Creo and Dassault Solidworks and similar OpenGL tools (see our specific notes regarding what types of OpenGL features are in the viewport for each test).

Benchmarks Results

We retested the AMD Radeon Pro W6600 at the same time we tested the Radeon Pro W6400. As you will see, in general across our typical cross-platform benchmarks we favor, the big-sister W6600 performs twice as fast if not faster than the W6400. It’s a battle between 768 Stream Processors versus 1792 Stream Processors.

CompuBench

We run the Catmull-Clark SubDivision Surfaces Level 5 test and the Subsurface Scattering rendering tests in this GPU-compute oriented, OpenCL benchmark suite. The algorithms in these tests are very applicable to real-world professional 3D computer graphics.

The algorithm tested here recursively breaks down surfaces into further surfaces to achieve “curved surfaces.” Software using the Catmull-Clark algorithm includes most leading CAD and 3D software tools from AutoCAD to Maya to Rhino. The W6600 GPU is essentially 2x faster than the W6400 GPU.

When it came to this particular rendering technique, Subsurface scattering (SSS), the big sibling AMD GPU again did 2x the performance of the subject test GPU. SSS is about how light penetrating the surface of a translucent object will scatter by interacting with the material before it exits the material on the other side. Shining a light behind your fingers is a real-life example of subsurface scattering. But the rendering test results look like this below. (Image 1)

Let’s look at some other tests, using OpenGL.

GFXBench

We only ran the GFXBench Tessellation OpenGL tests from this suite for this review. Tessellation is a critical technology in OpenGL performance and real-time rendering. Datasets of polygons are tessellated into triangles, and the process is offloaded onto GPU hardware to enable the smoothing of objects in real-time.

With only 42 percent of the stream processors and a bit over 1/3 the W6600’s TFLOP rate, it is very understandable why the Radeon Pro W6400 is half as fast or slightly less than its bigger sibling GPU on this computational function. This gives you an indication of where it sits in terms of rendering pipeline performance.

VRMark

AMD says the Radeon Pro W6400 is VR-Ready and our tests proved this case. The Orange Room test is the least demanding test and is designed to test VR performance today. So for headsets today the W6400 meets the mark.

The minimum FPS rate for powering the Oculus Rift or the HTC Vive (both devices that have been superceded but are variously available) a GPU needs to generate more than 90 FPS on this test. The NVIDIA A2000, a GPU costing twice as much, did well at 165 FPS. The AMD Radeon Pro W6400 scored 135 FPS. On a performance dollar basis, the W6400 slightly outperforms the NVIDIA A2000, but it neither matches it nor its bigger sibling W6600 in absolute performance.

SPECviewperf 2020 V3

For this review, we endeavored to add more information applicable to manufacturing CAD (MCAD) users. So we tested the Radeon Pro W6400 and retested AMD Radeon Pro W6600 we had recently reviewed on the SPECviewperf 2020 V3 benchmark.

SPECviewperf is widely considered the worldwide standard for measuring graphics performance based on professional applications. (learn more here). The benchmark test suite crunches through various “viewsets” from actual professional CAD and 3D applications including Autodesk 3ds Max, Autodesk Maya, Solidworks, Catia, Creo, and Siemens NX–without the need to have those applications installed on your machine.

Creo and Solidworks

In our tests, we selected viewsets for PTC Creo and Solidworks to focus solely on OpenGL 4.6 based MCAD systems.

So the first chart above shows the composite SPECviewperf 2020 scores for Creo. While the AMD Radeon Pro W6600 clearly out-classes its smaller sibling, the new Radeon Pro W6400 tells a more interesting story when we drill down into the details of specific subtests. (see charts below the next chart).

Again with Solidworks composite scores, the AMD Radeon Pro W6400 is out-classed by its bigger sibling, but not nearly as much as you might imagine based on TFLOPs and cores on the chip.

Shaded with Edges Tests

These MCAD industry tools are widely used with variously different rendering modes, but the dominant mode is working with models with “shaded and edges” rendered. This is the same way most AEC professionals work with BIM or 3D models. Transparency is also important, but reflections, bumps, textures, and anti-aliasing are of lesser importance and less commonly used.

In the Creo subtests, there are 13 separate tests. One test is called Scorpion, Shaded with Edges, no AA (anti-aliasing). This is a render mode that a large percentage of users will employ. Another common mode is the same thing but with anti-aliasing turned on, to smooth edges. World Car Shaded with Edges, 4xAA turned on is just such a case. (see images 2-3 below).  In both of these sub-tests, we see the Radeon Pro W6400 essentially nearly as performant as the Radeon Pro W6600, only off by about 4 percentage points max. (see chart 7 above).

However, in another sub-test called Scorpion, Shaded, Reflections, Bump transparency with color, 8xAA, we see the W6600 is nearly twice as fast. (see image below). Another view of the Scorpion model with HiddenLine, 8xAA, showed the W6400 GPU to be 58 percent as fast as its big sibling W6600.

What these Creo subtests demonstrate is that the W6400 GPU performs essentially at the same performance as its big sister W6600 GPU when working with models in viewports rendered in basic OpenGL shaded views with edges mode, with or without anti-aliasing turned on. This helps also explain the small differences between these two sibling GPUs with SketchUp models in many cases.

Economic Metrics

What we see above in the SPECviewperf 2020 tests is that in OpenGL 4.6 viewports rendered with complexity such as reflections, shadows (notice the shadow added in the image above), bumps, et cetera, is that the W6400 is outclassed by a mid-tier GPU like the W6600, which is what you would expect. So the type of OpenGL rendering can really matter in performance.

A majority of MCAD and AEC CAD/BIM users are working in viewports with shaded with edges mode with or without AA. So this is where the economics of the AMD Radeon Pro W6400 become interesting. Even in a mixed-mode where there is a blended mix of shaded with edges OpenGL rendered viewport work with more complex OpenGL rendered viewport work, the performance on a dollar cost basis is quite impressive.

On the composite Creo + Solidworks viewsets, the Radeon Pro W6400 has a better return on investment in terms of performance per dollar. And for those who do almost all their work in more simplified OpenGL rendered with shaded and edges only viewports, the economics then strongly favor the W6400 over the W6600. (see below).

The point of these last two charts isn’t to drive potential users away from the AMD Radeon Pro W6600 GPU, but to make the point that for a large majority of CAD users, depending on the type of work they do and how it is rendered in their OpenGL applications, the Radeon Pro W6400 will perform equally as well. This applies to AEC users, to some degree, as we see on the next page.

next page: Twinmotion, SketchUp, and Conclusions / Recommendations

SketchUp TTD FPS Tests

As we just noted in our last GPU review, SketchUp is quite symbolic of the prevalence of “CPU, frequency-bound” CAD industry applications. As Trimble notes, SketchUp is not multithreaded. In this way, it is very much like most BIM and CAD applications. We like testing with it because we can take our tests across platforms, which has always been important to our audience.

The question that one might want to know about the W6400 GPU is, is it good enough for massive SketchUp work? As we will see in the chart below, the answer is most definitely.

Our three test files range in size from 1.3, 13, and 200 megabytes. We run the “Test.time_display” FPS test that Trimble has shared in its user forums. You can learn more from our last article about these tests and how to run your own SketchUp TTD FPS tests.

As you can see from the composite scores from our SketchUp TTD FPS test, the Radeon Pro W6400 performed at 93 percent of the speed of its bigger sibling GPU, the W6600. As noted here and here, going beyond the Radeon Pro line’s mid-level GPU isn’t going to gain you much. The one caveat would be those working with files much larger than our 200MB file with tons of textures and when one is working with shadows and effects like fog.

Twinmotion and Raytracing

We spent so much time testing the Radeon Pro W6400 in benchmarks like SPECviewperf 2020, doing more thorough SketchUp tests and recordings, that this review had to give a bit somewhere. We quickly ran through our Twinmotion file and noticed that the image quality was clearly on par with both the AMD Radeon Pro W6600 and the recently reviewed NVIDIA RTX A200o. (Image 5)

We navigated, panned, zoomed, and selected elements and generally felt that the AMD Radeon Pro W6400 did a pretty darn decent job at Twinmotion. You can see we had AMD Radeon Pro software’s performance overlay stats on the upper right in the image above. Note, we are at full capacity with the VRAM and nearly 100 percent GPU utilization. This image was captured doing a lateral pan.

Compared to the aforementioned two GPUs above, micro stutters were a tad bit more noticeable. During panning operations or camera pans moving in and out, frame rates were still quite smooth.

Conclusions and Recommendations

The AMD Radeon Pro W6400 was built for a wide audience of pro users, across multiple markets. It is designed to address both modern, multi-function business workloads (from video calls to Excel to photo editing) while also being suited as a GPU entry-point for CAD/BIM workstations, especially small-form factors (SFF) workstations.

As an entry-level workstation GPU, this unit shines in two areas. Firstly, by delivering excellent performance for “shaded with edges” typical CAD workflows, including in MCAD tools (not just AEC) and especially on a performance per dollar basis. And secondly, by delivering real-time raytracing to power those same users just mentioned who on occasion venture into real-time rendering tools (particularly growing in AEC).

There is so much to like in this Radeon Pro W6400, from its SFF flexibility to its astounding price and performance per dollar metrics. This is an excellent GPU workstation option for more senior-level staff in architecture offices who need to access BIM and 3D models on a half-time or less basis and infrequently render. On a comparative return on investment basis, it is questionable if spending twice as much on the more powerful NVIDIA RTX A2000 would be as smart as taking that extra 230 USD and upgrading to a higher-performing CPU. If you live in the land of designing in OpenGL “shaded with edges” rendered viewports, the AMD Radeon Pro W6400 is smart money!

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