Original Link: http://www.anandtech.com/show/2380
NVIDIA GeForce 8800M: Fast DX10 Mobile GPUs Finally Arriveby Jarred Walton on November 19, 2007 12:00 AM EST
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It has been more than a year since NVIDIA released their GeForce 8800 GTX graphics chip for desktop computers - a chip that remains to this day the fastest gaming GPU (if we include the 8800 Ultra update). We've heard lots of talk during the past year or two about DirectX 10 and how it would enable improved performance and better graphics. However, only recently have we started to see games that actually utilize the technology, and we're still waiting for performance increases. Still, there is little doubt that DirectX 10 is the future, and NVIDIA is ready to embrace the technology on all levels with the introduction of the GeForce 8800M GTS and GTX.
Six months ago, NVIDIA released their first DirectX 10 multiple graphics chips, but a decidedly large gap remained between performance laptop and desktop hardware. In fact, there were quite a few areas where the last generation GeForce Go 7950 GTX outperformed the latest and greatest DX10 GeForce 8700M GT. Simply put, at the time it was necessary to remove too many features in order to reach the target power envelope. Where performance desktop GPUs had 96 or 128 Stream Processors (SPs), the mobile offerings topped out with one-third the number of SPs.
Earlier this month, NVIDIA launched their GeForce 8800 GT to nearly universal praise and high demand. Many of the elements that make the 8800 GT so attractive match up very well with the mobile market: smaller size, higher performance, and lower power requirements. Most of these benefits come from the new 65nm process technology, which is why we haven't seen high-performance DX10 mobile parts until now. The result is that nearly all of the features and performance currently available on the desktop will soon be coming to notebooks from a variety of manufacturers.
Unfortunately, we were unable to get an appropriately equipped laptop in time for this article. We expect availability starting in early 2008 - with pre-orders starting shortly - from most of the usual suspects for gaming notebooks. We should have one of the first 8800M GTX production notebooks in the near future, at which point we will be able to say something more about actual performance. However, there's still plenty of other information to cover, so we will begin with an overview of the market along with a look at the specifications of the upcoming GeForce 8800M products.
Why Do Laptops Matter?
It never fails that whenever the subject of gaming notebooks comes up, someone asks: why should we bother? Won't we always get better performance in a desktop, and at a more reasonable price? That has always been the case, and we see no reason why this should ever change. Size and power requirements invariably dictate that it is easier to put more powerful components in a desktop system. That does not mean that everyone needs or even wants a desktop.
One of the most common examples that we've encountered is people serving in the military; lugging around a full-size desktop can be more than just inconvenient for such a user. College students are another good example of people that might get more use out of a notebook. Many businesses are also finding that notebooks are better than desktop computers, and plenty of home users find the ability to surf the Internet throughout the house to be desirable. To the earlier question, we counter: why do we need to have a large desktop taking up space if we can do everything we want from an easily transportable notebook? Market research indicates this sentiment is growing in popularity, as seen in the following slide.
We are fast reaching the point where the need for improved performance is no longer a driving concern for most users. We can see many areas where dual-core processors are extremely useful, but quad-core is absolutely overkill for the average person surfing the net, writing documents, managing spreadsheets, and even playing games. We will eventually see the point where quad-core becomes ubiquitous, but plenty of users and businesses continue to function with no difficulties on computers that are several years old. When those groups are finally ready to upgrade their aging desktops, stepping up to a moderate laptop makes a lot of sense.
The time of "one-size-fits-all" computers is long past, and having a good idea of what you plan to do with your computer helps tremendously when it comes time to upgrade. While there will always be people that prefer desktops for certain uses - 30" displays and workstations doing serious number crunching for example - for most others mobile computers are now worth considering. Laptops continue to cost more, but decent laptops start at less than $1000, at the very least making them worth a second look. How does graphics performance fit into the equation? Let's turn our attention to the star of today's article for the answer.
GeForce 8800M GTS and GTX
Obviously, the big news of the day is that NVIDIA has a couple new mobile graphics chips available for notebook manufacturers. Before we get into the details, here's a quick breakdown of NVIDIA's mobile GPU offerings for the past two years. Naturally, the GeForce 8800M GTS and GTX take their place at the top of the performance totem pole.
Despite the fact that NVIDIA lists the 8700M GT as an "enthusiast" part, we would be inclined to place it down a notch with the 8600M GT. The primary difference between the two parts is core clock speed, as both include 32 SPs. Similarly, we would demote the 8600M GS to a mainstream part, considering it only has 16 SPs. While all of the DX10 mobile offerings will outperform current integrated solutions, anyone interested in gaming performance should really set their sights at the 8600M GT as a bare minimum. The following list of specifications and features should make our reasoning clear.
While we wouldn't go so far as to call the 8700M GT slow, the 8800M GTX is clearly a major leap in performance. Besides having three times the number of SPs, the 8800M GTX has a 256-bit memory interface. Taking default clock speeds into account, the 8800M GTX offers 140% more fillrate, three times the pixel processing power, and twice the memory bandwidth. The 8800M GTS also has twice the memory bandwidth, but because of the reduced number of SPs it only has 60% more fillrate and twice the pixel processing power - still enough to make a noticeable difference in gaming performance.
Looking at the features chart, we can see that all of the GeForce 8M graphics chips are similar, with a few areas of differentiation. The 8400M G is the only card that lacks the newer VP2 video processing engine, while all the other GPUs should be able to handle full 1080p H.264 decoding. Maximum resolutions are also slightly lower on the 8400M cards. Note that while all of the higher-end cards are capable of supporting 2560x1600 resolution, that requires a dual-link DVI output and the inclusion of such will be up to the notebook manufacturers (unfortunately). Everything from the 8600M GT and above will also support SLI, for users that want the absolute fastest possible graphics performance in a notebook.
NVIDIA provided us with some images of the MXM (Mobile PCI Express Module) boards for the 8800M GTS/GTX. While they did not officially confirm our suspicions, it appears that the GTS variant uses the same basic chip as the GTX, only with 32 of the SPs disabled - perhaps in order to improve yields. Modules will be available for MXM3 and MXM4 (but not MXM1).
So what sort of power requirements will come with these new ultrafast mobile GPUs? Here is one more area where things have improved over the GeForce Go 7950 GTX. Maximum power use should be somewhat lower (37W compared to 44W for the 8800M GTX, and a few watts lower for the 8800M GTS), and minimum power requirements should also be lower - we were told the 8800M GTX sitting idle at the Windows desktop consumes 4.7W. VP2 will increase power requirements slightly when watching movies, but only up to around 7.2W. While the idle power consumption isn't particularly high, the fact of the matter is that battery life is extremely important for many laptop users, and battery life will still suffer compared to IGP laptop offerings.
The Holy Grail for laptops would be to have a system that can completely shut down any discrete graphics card(s) when 3D performance is not required. That would potentially allow manufacturers to create even SLI notebooks that could still offer several hours of battery life - provided you're not running any 3D applications. NVIDIA is at work on creating such a solution, which they are calling hybrid graphics. The technology is not yet finished, and there's more to it than simply shutting down the discrete graphics. Still, the idea is promising and we certainly look forward to being able to have our cake and eat it too when it comes to gaming notebooks and battery life.
DirectX 10 Games and Initial Performance Estimates
Up until recently, the need for DirectX 10 hardware has been debatable - only a few titles have even supported DirectX 10, and performance has often been too slow to warrant consideration. With the holiday season in full swing, however, top-end DirectX 9 hardware from last year is now beginning to seriously struggle on many titles. Recent releases such as Crysis and Hellgate: London are just the tip of the iceberg. DirectX 10 mode might still be too much for many graphics cards to handle, but the latest DX10 hardware is also substantially faster at running DX9 code. The following slide shows the growing list of DX10 enabled games.
Huxley and Call of Duty 4 could also be included in that list, and there are many more titles scheduled for release in the next year that will continue to push GPU requirements.
So just how fast is the GeForce 8800M GTX? As mentioned, we were unable to test one in person at this point in time, but we will provide detailed results as soon as possible. In the meantime, here are a few quick slides from NVIDIA showing preliminary performance results. Note that we are not in control of the test variables for the following slides, and the first 3DMark06 slide includes three different CPU speeds (2.8GHz for 8800M, 2.2GHz for 8700M, and 2.0GHz for 7950 GTX). As gaming continues to be predominantly GPU limited, however, these baseline performance estimates should at least whet your appetite.
It appears that we should be able to get approximately twice the performance of the GeForce Go 7950 GTX (and more than twice the 8700M GT) with the 8800M GTX, which brings laptops back into striking range of desktop computers. A single 8800M GTX should also be roughly the same speed as GeForce Go 7950 GTX SLI, without the hassles of SLI drivers and profiles. For those that simply demand top performance, we can expect 8800M SLI configurations to improve performance again by up to 80% - just don't worry about battery life on such notebooks.
While we would love to have hardware in our hands for this product launch, that is frequently not possible for the mobile market. NVIDIA is working with various manufacturers, many of whom are in the final stages of testing and validation, and we expect to see 8800M notebooks begin showing up online for pre-order shortly. If you're interested in picking up one of these systems, you might keep an eye on the websites of the following companies.
Before you take the plunge, we'd like to close things up with a few final thoughts. One of our biggest concerns with any gaming notebook continues to be driver support. We brought this up with NVIDIA, and we weren't surprised to find that the major difficulty appears to be notebook manufacturers. A lengthy series of testing and validation procedures is typical, and this is unfortunately required for every driver update. The result is that it can often be months (if ever) before you see new graphics drivers. That might not be a problem if all you want to do is run Windows Vista and surf the web, but for anyone playing games this is a serious concern. We went so far as to state bluntly, "There is absolutely no purpose in making a gaming notebook if you don't intend to provide the users with timely graphics driver updates!"
To their credit, NVIDIA seems more than willing to work with notebook manufacturers, but most of the manufacturers don't appear to understand the importance of driver updates. We encountered this problem when we reviewed the Toshiba X205 notebook a few months back. The latest Toshiba driver (which is yet to be updated!) does not function properly with several of the latest games - for example, we were forced to look for hacked drivers in order to run Bioshock. Call us crazy, but we don't think users should be required to hack their own drivers on a gaming notebook. Our advice is that before you go out and purchase any notebook with the intent to play games, first take a look at the company website and find out how frequently they have updated drivers on previous models - unless you don't mind downloading hacked drivers, of course.
Beyond the question of drivers, arguably the biggest barrier to entry for gaming notebooks is price. "Inexpensive" gaming notebooks usually start at $2500, and it's not unusual to see higher performing models selling for $4000 and more. When you can purchase a very good desktop for gaming and a more moderate notebook for other uses and still save $1000, it's going to be a tough sell for most people. While we don't expect to see notebooks sporting 8800M GPUs priced for $1500 or less anytime soon, NVIDIA did inform us that several companies are working on models starting at $2000. Many consider $2000 the sweet spot for performance notebooks, so we are definitely interested to see what manufacturers can put together targeting that price.
One other complaint that many people have with gaming notebooks is their size. Because of the higher power requirements, most gaming notebooks utilize a 17" chassis (or larger). While some people are willing to deal with a larger, heavier notebook, many would prefer something smaller. NVIDIA informed us that at least one manufacturer is working on a 15.4" chassis equipped with a GeForce 8800M GTX. Again, that is something we definitely look forward to reviewing.
In the grand scheme of things, today's launch of the GeForce 8800M may not seem particularly noteworthy. Most of us figured NVIDIA was working on a faster DX10 mobile part; others were wondering what was taking so long. The 8800M is definitely a nice improvement over the previous top-end mobile offerings, but NVIDIA really hasn't faced much competition in the mobile performance market. AMD/ATI has been content to release midrange and low-end parts, but with plateauing performance requirements and increasing notebook sales, perhaps they will once again enter the high-end gaming notebook sector. Until that happens, the 8800M GTX remains your best bet for gaming on the go - once they actually become available for purchase.