Patriot Viper 2x1GB DDR3 PC3-15000 Review

We are going to start off with a quick test fit in the Asus Maximus Extreme before moving the modules over to the Asus P5K3-Dlx that they will be tested in.

It is pretty much the same song and dance with these modules as we saw with the Super Talent Project X and like we will see with any other module that has above average height heat sinks. With the Thermalright Ultra-120, or any other large heatsink with a hefty wing span, there may be interference in the first DIMM slot. Of course, with the Ultra-120, all it takes to alleviate this issue is to rotate it and voila; all four slots are usable with the Viper Fin heat sink. This isn't a major issue but something to keep in mind when piecing a system together or upgrading your cooling.

The Asus P5K3-Dlx is a little different because the CPU cooler, even the Thermalright Ultra-120, doesn't interfere with the first slot. Instead, it is the Noctua NC-U6 chipset cooler that we have installed for additional cooling of the north bridge. It is a known fact that the black slots on the P5K3-Dlx are designed to clock memory better so losing the orange slots on this machine really is no big deal as we never use them. Obviously with the stock chipset cooling of the P5K3-Dlx, there are no installation issues in either slots unless you have one monster CPU cooler...and they are out there but that is the CPU coolers fault, not the memory's.

Looking at the CPU-Z screenshot above to the left, it is obvious that there is no XMP profile listed. This is because we received an early sample of this memory and Patriot hadn't yet began implementing the XMP enabled SPD profiles. Going forward, all Viper Extreme PC3-15000 will come with XMP profiles programmed in the SPD profile. Because we don't have the ability to use the XMP profiles on the Asus P5K3-Dlx even if these modules had them, we have to manually adjust the FSB in order to get this memory to run at specification. The CPU-Z tab to the right shows us that we don't get the full specifications when manually setting the FSB to get the memory running at 934MHz and leaving the timings set to AUTO. This means that we will have to adjust the timings to 8-8-8-24 in the BIOS manually. For those that haven't done these sort of timing adjustments, that little leaflet that Patriot includes goes a long way as it provides enough information to accomplish this task.

Test Platform:

• Motherboard: Asus P5K3-Dlx
• Processor: Intel C2D E6850
• Processor Cooling: Rosewill RCX-Z775-EX
• Memory: Patriot Viper Extreme DDR3 PC3-15000
• Power Supply: Thermaltake Toughpower 700W
• Video Card: XFX Alpha Dog 8800GTS 512MB
• Additional Fans: 120mm AD1212MS-A73GL 2050RPM/80.5CFM
• Hard Drive: 1 x Seagate 7200.9 80GB SATAII 8MB cache
• OS: Windows XP SP2 (with recent updates)

This discussion has be avoided for the most part up until this point and that is because we were saving it for its own section. The specified operating frequency of this Patriot Viper Extreme memory is DDR3-1866 or 933MHz at timings of 8-8-8-24 with 1.90v. In order to reach this frequency, the system must be overclocked and the FSB raised to a lofty 467MHz. Not only is this a significant FSB increase but simply running memory at 933MHz is never guaranteed on any motherboard. Many P35 based motherboards may have trouble running memory stable at this frequency. Our P5K3-Dlx used in testing has not been stable above 960MHz with any kit of memory and has shown instability as low as 950MHz with some kits.

It is safe to say that not all motherboards have the ability to run this memory at specifications. This must be kept in mind when purchasing high-end memory like this Patriot kit. We have entered an era where the top DDR3 memory kits available to us today are actually out-running the chipsets, motherboards and CPUs in the system. The Intel X38 chipset is somewhat better but again, there is no guarantee that all motherboards will have the ability to run 467MHz FSB or 933MHz memory. In fact, a lot of quad-core processors have had issues reaching 467MHz FSB, especially the newer 45nm QX9650s. With that said, this kit can still be of great use because running at 8-8-8 for maximum frequency isn't always required and that is why we do our overclock testing at tighter timing sets in conjunction with looser timings like the specifications outline. We will now see if this memory is able to pass our stringent stability testing at stock specifications and how far it will overclock at various timing sets.