Some Observations on the

Asrock 775Dual_VSTA Motherboard

Let me start by clarifying that I'm not going to try to do a full fledged review of this interesting motherboard.  You can find in-depth examinations of the 775Dual-VSTA over at  Overclock Workbench and Legit Reviews, for example.  Furthermore, Anandtech put considerable time into investigating this motherboard.  In addition to their initial preview, they ran a series of articles delving into various aspects of this motherboard's performance.  First, they compared DDR vs DDR2 memory performance, using this motherboard.  Next, they looked at how memory performance on this motherboard measured up to the memory performance of other Conroe motherboards, which included motherboards using a variety of chipsets.  Finally, they compared the video performance of this motherboard's AGP slot to its PCI-Express slot.  What is there left to say about this motherboard?  Perhaps not a lot; so, I'll try to focus in on some smaller details that might have been overlooked or at least not emphasized in the more elaborate articles.

[January, 2008 Update

I recently had the opportunity to try out an 8800GT PCI-E video card on this board.  I discovered that the board will not boot up with this video card.  The 8800GT is one of the first video cards designed around the PCI-E 2.0 standard.  It is suppose to be backward compatible with PCI-E 1.0 motherboards (since only one chipset currently is supporting PCI-E 2.0, Intel's X38 chipset), but this appears to be broken in the case of the 775Dual-VSTA motherboard.  With the 8800GT installed, the monitor fails to get any video signal; stubbornly remaining blank while you try to boot up your computer.  (Interestingly, ATI's new PCI-E 2.0 video cards, the HD 3850 and HD 3870, seem to work fine on the 775Dual-VSTA.)

There is some discussion of the 8800GT problem over at Hard Forums, in this thread.  There, I learned about a workaround for getting an 8800GT operating on the 775Dual-VSTA; however, this  involves changing the video card's BIOS.  This is not for the faint of heart, since you risk making your video card inoperable, if you screw this up.  You  also void the warranty on your new video card in the process.  But, if you are comfortable with taking matters into your own hands and if you have access to another motherboard that your 8800GT  works with, you can find the information to get you started in the above mentioned Hard Forums' thread.  You probably should also take a look at Nibitor, the Nvidia BIOS Editor.  You can find more information about this utility at the author's website, including a forum thread about using this tool to make the necessary changes in the 8800GT BIOS.  

I personally cannot attest to the process of modifying the 8800GT's BIOS.  I  already bought a new motherboard, before I read about this fix.  I'm content with this solution, since I'm looking forward to seeing how well my E6600 processor will overclock on a motherboard with faster bus speeds available.  I hope to have information on that soon, after I've had a chance to try out the new motherboard, a Gigabyte GA-P35-DS3L.  I'll post some results when I get through.]

[February, 2008 Update

It looks like Evga has officially made available a BIOS update to address this issue of compatibility between the 8800GT and some motherboards.  This update also changes how the fan functions; now, the graphics chip should stay cooler than it did previously.  From here forward, all new Evga 8800GTs will have this BIOS; so, this motherboard compatibility problem should not be an issue for future purchasers of this card.  I would assume other 8800GT manufacturers either have or will do something similar, but I don't have any information on that at the moment.

(This new BIOS is also available on the mvktech website, if you prefer to install it using nvflash  Look for the 62.92.24.00.01 BIOS for your particular model in Evga's 8800GT lineup.)  

Now, back to my previous discussion of the Asrock 775Dual-VSTA.]

Who should consider this Asrock motherboard

For those who are not familiar with this motherboard and would like to save reading the above mentioned reviews for a later time, I'll summarize what makes this an interesting motherboard.  Asrock established a niche for themselves by designing motherboards that offer great flexibility in the range of hardware that they can be used with, and they offer these unique designs at a price point that is typically found at the "budget" end of the motherboard price range.  The 775Dual-VSTA follows these principles.  It is a 775 socket motherboard that supports the latest Core 2 processors from Intel.  Uniquely, it also offers support for both DDR and DDR2 memory and for both AGP and PCI-Express video cards.  You can purchase this motherboard (or at least its upgraded replacement, the 4CoreDual-VSTA) for about $60 at this time from NewEgg, for example.

This motherboard's niche not is really the high-performance, enthusiasts' market; rather, this motherboard is offered as a stepping-stone motherboard for do-it-yourself computer builders, who are looking to upgrade from their current AGP and DDR based rig to something that will support Intel's Conroe processors, especially if they would like to avoid replacing everything (motherboard, CPU, memory, and video card) all at the same time.  If you already have a fast AGP video card and/or 2GB of DDR RAM, the 775Dual offers you a path for upgrading to a speedy Conroe based processor, while continuing to get some more use out of your DDR memory and your AGP video card.  And, you can continue to use this motherboard as you incrementally upgrade to DDR2 memory and a PCI-Express video card, down the road.  Although the 775Dual_VSTA's PCI-E video card slot only provides PCI-Express 4X bandwidth, this only appears to cramp the fastest video cards (and even these cards only lose up to 10% of their performance on this board).  So, it certainly is conceivable to upgrade from an AGP to a PCI-E video card, while continuing to use this motherboard as a interim step.

My Asrock experience

How well does this motherboard deliver the goods for someone looking for this kind of an upgrade experience?  I had been running an Athlon XP system, using a mobile Athlon XP overclocked to 2.3 GHz on an Epox motherboard with an nvidia chipset.  I had 1.5GB of DDR-400 memory, using a mismatched pair of modules (a 512MB Mushkin module and a 1GB Patriot module).  My video card was a Leadtek 6800GT.  Through my previous upgrades, I had reached the point where I felt that my Athlon XP processor was the primary bottleneck in my system, limiting the performance I could get while playing computer games.  So, I turned to the Asrock 775Dual-VSTA as a way to upgrade to a significantly better processor, while having the option to hold off on upgrading my video card.  At the time, I didn't know if the 775Dual-VSTA would support a mismatched pair of DDR memory modules; so, I went ahead and upgraded to a dual channel DDR2 memory kit, too.  As it turned out, this was unnecessary; the 775Dual-VSTA supports both single channel and dual channel memory configurations.   

I bought my 775Dual-VSTA back in November, 2006, and at the time it came with BIOS version 1.7.  This version turned out not to fully support the Crucial Ballistix DDR2-800 memory that I had just purchased.  Even running it at DDR2-533 speeds, with relaxed timings, and high memory voltage, the system still generated errors on MemTest86.  I had to resort to the Memory "Flexibility" option in the BIOS, which essentially sets the memory speed to DDR2-400, in order to run this Micron memory error free.  This did give me an opportunity to upgrade the BIOS to v2.10, and  the memory has run fine at DDR2-533 and DDR2-667 speeds since then (it doesn't offer a DDR2-800 option).  I've been able to push the timings down to 3-3-2(tRP)-8-2T at DDR2-533 speeds, and I've been able to run at DDR2-667 with 3-4(tRCD)-3-9-2T timings.  I've not had much luck with the 1T command rate.  However, let's not get too focused on the memory timings at this point; I'll have more to say about different memory configurations and performance, later.

[A safer route that I could have taken, when I discovered the problems running my DDR2 memory on this motherboard, would have been to install the DDR memory that I had and flash the BIOS using it.]

Once everything was running properly, one of the first things that I was interested in finding out was whether my upgrade to an Intel E6600 Conroe (2.4 GHz, 4MB cache) had improved my video rendering performance, using my existing 6800GT video card.  I was pleased to see that it had.  With my previous system (2.3Ghz Athlon XP processor), I was getting an Aquamark 3 score of 56,320, but with the faster processor, my Aquamark 3 score jumped up to 73,939.  I felt like I now was getting the full potential out of my 6800GT.  (It even seemed reasonable to consider overclocking my video card, since there no longer was a CPU bottleneck to contend with, but we'll get to that a bit later.)

Different memory configurations and how they perform

Of course, even seeing this improvement, I wasn't deterred from exploring whether I could tweak a bit more performance out of this system.  I started by looking at the memory settings to see what gains might be made.  Although some differences in the memory bandwidth could be detected (using Sandra's Memory Bandwidth test, for example), the impact that this had on my system's overall performance was fairly negligible.   This was consistent with what Anandtech reported in their investigation of different memory configurations.  The bottom line seems to be that the Conroe processor is not limited to any significant degree by any of the various memory configurations that this motherboard supports.

Below are the Memory Bandwidth scores from Sandra (v2007.3.11.22).  I noticed that Sandra's memory scores can vary a fair amount (up to 200 points) over the course of several re-tests, even when no hardware or settings have been changed; so, you shouldn't make too much of any small differences in these scores.  

Despite the lack of inter-test reliability with Sandra's memory  benchmark, I think we can conclude DDR memory (whether dual or single channel) does not offer the same amount of memory bandwidth as does any DDR2 memory configuration on this motherboard.  And, as has been noted by other reviewers, this motherboard appears to be optimized for running DDR2-533, dual channel memory, as this configuration scores significantly better than any other configuration. 

However, despite these apparent differences in how well different memory configurations work on this motherboard, it turns out that the impact of these memory differences is much less significant on other measures of computer performance.  

Benchmarks that tend to isolate the CPU and the memory subsystem seem to show the most effect.   For example, below are the benchmark results from Prime95, a number crunching program.

You can see that the DDR memory is slower than the DDR2 configurations, at least when Prime95 is working with the larger 4096K numbers.  On the other hand, the memory bandwidth differences that we saw between DDR2-533 dual channel and DDR2-667 dual channel configurations make no apparent impact on the Prime95 scores.  (In fact, the DDR2-667 scores seem slightly faster, despite the previously noted lower bandwidth compared to DDR2-533 dual channel.) 

WinRAR's built in benchmarking utility shows essentially the same picture, as seen below.

When we turn to the more complex task of rendering 3D game video, it is no longer possible to discern any significant differences among these different memory configurations.  They are all much more alike than they are different.

Overclocking

As it appears that different memory configurations, ranging from DDR-400 to DDR2-667, make very little difference to the performance of this system (especially when it comes to computer games), I found myself wondering whether overclocking might yield some improvements.  Unfortunately, this motherboard doesn't really offer too much room for overclocking, if you are running a processor that requires a 266 MHz front side bus (1066 MHz quad-pumped).  The fastest bus speed that I could reliably boot into with this motherboard was 288 MHz.  Although this is a bit on the low side for this motherboard (as others have gotten into the mid 290's), you really can't count on anything much above 300 MHz with this motherboard.

I was able to find out quite a bit about others' experiences with this motherboard by reading through the 775Dual-VSTA thread in Anandtech's Motherboard Forum.  They also have a  newer thread for the 4CoreDual-VSTA.  One tip that I picked up there was to set the AGP voltage to high in the BIOS.  Apparently, this increases the voltage to the Northbridge chip, and it helps a bit with overclocking the frontside bus.  In my case, however, this only meant that I could increase my fastest reliable overclock from 286 MHz to 288 MHz.  At the stock AGP voltage, my system would sometimes fail to finish booting at 288 MHz, but I've not had that problem with the higher AGP voltage setting. 

Below, I've laid out information on what the BIOS voltage settings mean, as they have been described in the above mentioned Anandtech Forum thread.  You'll note that there is no listing for a Vcore voltage settings, since the BIOS does not support changing the voltage for the CPU on this motherboard. 

Although my processor didn't have much room for overclocking on this motherboard, Intel has expanded their Core 2 Duo line to include CPUs based on the Allendale core.  These processors, the 1.8GHz E4300 and the 2.0 GHz E4400, run on a 800 MHz frontside bus.  This lower default bus speed leaves much more room for overclocking.  Going from 800 MHz to around 1160 MHz represents an overclock close to 45%. 

With only an 8% increase in speed for my Conroe based CPU, I wasn't surprised that the benchmark scores didn't show any significant improvements.  The synthetic memory benchmarks were able to detect some improvements with the faster front side and memory bus speeds; and, the purely processor intensive benchmark Prime95 showed some slight improvements; but, the game benchmarks showed no real differences over the stock settings.

With my upgrade to Core 2 Duo E6400, the CPU is probably not the limiting factor in game performance, now, anyway.  My 6800GT capabilities seem more likely to be the bottleneck in 3D rendering.  Using the Nvidia Control Panel, I used the overclocking option to find the "optimal" overclock for my video card.  This bumped my settings up from 350 MHz core/ 1000 MHz memory to 390 MHz core/ 1040 MHz memory.  (For comparison, the 6800 Ultra's default settings are 400 MHz core/ 1100 MHz memory.)  These gains in clock speeds did provide a modest improvement in my game benchmarks.

Conclusions

I think that the main thing that I can say to sum up my impressions of this motherboard is that I am still quite satisfied with it, after using it for about six months.  The capacity to upgrade my processor to a relatively powerful Core 2 Duo CPU has breathed new life into my video card, allowing me to continue to enjoy my current games.  I know that there are a couple of new generations of Nvidia video cards available (the 7000 and the 8000 series cards), but I don't see a need to upgrade to one of these until some new game comes along and overwhelms my current video card's abilities.  Presumably, by the time that occurs, I'll have an even wider choice of more powerful and affordable video cards to chose from.  I also would consider replacing this motherboard at that time, since I may find it worthwhile to see how far I can overclock the CPU, once I have a faster video card.  A much wider selection of motherboards supporting the Core 2 Duo processors is now being produced, compared to six months ago, and these should continue to become more affordable over time. 

Given that I bought this motherboard with the idea of just using it as an intermediate step in the process of  a more complete overhaul of my system, I'm happy to say that it has provided me with a comfortable way to continue enjoying my older video card, by matching it with a faster processor and newer memory.  After six months, I feel no rush to replace either this motherboard or my AGP video card.      

April 28, 2007