Stability Testing & Overclocking
<b>Stability Testing & Overclocking:</b>
<p style="text-align: justify;">Our stability testing methods for memory have been discussed at length in the past, so we are going to simply rely on the explanation from previous reviews. Here is a run-down of what we consider to be stable.</p>
<b>Stability Testing Methodology:</b><p style="text-align: justify;">Memory stability, what constitutes stable? What is not considered stable? These questions get hotly debated in enthusiast forums all over the internet like little brush fires on the fringe of an inferno that play havoc with forest fire crews. Everyone has their own opinion about stability, especially when it comes to memory stability. For some, stable means they can do whatever it is on their computer without it crashing, blue-screening, or restarting; whether that means gaming or just surfing the internet. To this user, stable means simply using the computer as they normally would.</p><center><img src="http://images.hardwarecanucks.com/image/3oh6/gskill/F3-12800CL7D-4GBPI/setup-3.jpg" alt="" border="0"></center><p style="text-align: justify;">Of course, that is not what we would call stable and we do a lot more thorough testing before labeling a memory frequency/timing stable. One of the toughest types of programs on a system has been found to be distributed computing projects such as Rosetta@Home, Folding@Home, World Community Grid, and more. Running 24/7 crunching for one of these great causes is a sure way to find holes in a system if there is truly some instability, unfortunately it takes a considerable amount of time to use them for stability testing so we use the list of programs below to all but guarantee the system to be
24/7 distributed computing stable:</p>
<p style="text-align: justify;">Obviously this type of stability testing is for a 24/7 setup as mentioned but it is also very thorough testing a number of different programs that can find instability. We will also show lower levels of stability from time to time but will explicitly outline that we are only showing a specified level of stability. Keeping the above requirements in mind, let's find out if the G.Skill 4GBPI kit is going to give us a hassle at the XMP defaults.
<b>
Specification Stability Testing:</b>
<p style="text-align: justify;">Coming into receiving this kit, the most important thing that seemed to be needed by readers was whether or not this memory was stable at the specified frequencies and timings. As well as which motherboards the memory is compatible with. 2x2GB kits of memory seem to really be pushing DDR3 memory controllers at frequencies that 2x1GB kits have no problem running. We will keep this in mind when testing all of our 2x2GB DDR3 memory kits. Here is the screen shot of this G.Skill PI PC3-12800 2x2GB kit running the XMP profile out of the box without so much as a hiccup.</p>
Click for full size screenshot...
<center>
</center><p style="text-align: justify;">As mentioned, there were no issues during testing these modules running their XMP profiles and performance was quite good. The XMP profiles would only select a Performance Level or tRD of 7 but the motherboard should easily be capable of PL6 at 400FSB and would like to see this added to the XMP profile. The screen shot above I actually set PL6 manually and had no issues throughout testing. Let's now talk about our battle with our ASUS P5E3-Premium and clocking these G.Skill sticks.</p>
<b>
Stability Overclocking:</b><p style="text-align: justify;">We have to preface this section with the disclaimer that our ASUS P5E3-Premium doesn't like us at all. This review has been pushed to the absolute limits in trying to get this combination clocking but we have just run out of time. Normally, memory doesn't put up much a fight with the hardware we use but the recent addition of the ASUS P5E3-Premium left us in un-familiar ground with the motherboard and the results show. Naturally, we were able to squeeze a good bit out of this kit, even at very low voltages with just the motherboard holding us back at this point. Because of these difficulties, we will for-go the usual clocking and show a bit more fragmented version of what we have been able to achieve. Let's start with the first screenshot that we ran within days of getting the kit. At this point, this is still the highest fully stable screenshot we have.</p>
Click for full size screenshot...
<center>
</center><p style="text-align: justify;">At just above stock voltage, we were able to run the memory easily up to the 830MHz mark. This is with the same tight timings provided by the XMP profile. The excitement for this kit was there early but we were just unable to go any higher. Loosening up timings did nothing for progress, neither did BIOS changes. We did find that overclocking improved when moving from the black slots to the orange slots, but the same gains could be found increasing CLK skew with both being limited to around 880MHz or DDR3-1720 at 7-7-7 or any timing set really. Here is a screenshot of dual 32M SPi stability at 1.90v. Keep in mind, this is just dual 32SPi stable, it may be fully stable but it may also need to drop 10~15MHz for full stability.</p>
Click for full size screenshot...
<center>
</center><p style="text-align: justify;">As we can see, there is a lot of potential in this kit of memory, we just weren't able to un-lock it unfortunately with our motherboard. We also did some testing at tighter timings but lost a reasonable amount of frequency when trying to run at 7-7-6 or 7-6-6. Either way, these modules look to provide some decent headroom for those looking to go past 400FSB on the 1:2 ratio.