Patriot Viper II Sector 5 PC3 20000 Cas 9 4GB Reviewccokeman -
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Testing the Patriot Viper II Sector 5 2500MHz rated modules will require a modification to the existing test setup. My trusty little i5 750 is a trooper, but just does not have the bclock capability and memory dividers to get these modules to 2500MHz, let alone any higher. That means it's time to bring in the big guns and allow the i7 875 some time to stretch its legs. Even so, it's going to take a 209MHz bclock to get the modules to 2500MHz speeds. With this set of modules, it's go big or go home. There are few modules to compare to this set, with the best set of modules I have running out of steam at just about 2200MHz, so I will show the performance of the modules at their rated speed as close to the default frequency of the 875 as I can get, while keeping the modules at their rated speed to minimize the effects of overclocking the processor to reach the rated speed of the modules.
- CPU: Intel Core i7 875
- Motherboard: ASUS Maximus III Formula
- Memory:Â Patriot Viper II Sector 5 PC3 20000 Cas 9 4GB kit
- Video Card: Sapphire HD 5870
- Power Supply: Mushkin 800 watt Modular Power Supply
- Hard Drive: Seagate 1 TB 7200.11 SATA
- Optical Drive: Asus DVD-R
- OS: Windows Vista Ultimate 64-bit SP1
- Comparison Module #1: Mushkin BlackLine 996782 PC3-12800
- Comparison Module #2: Kingston HyperX
- Comparison Module #3: Corsair Dominator
- Comparison Module #4: Patriot Viper II Sector 5
- Comparison Module #5: Mushkin 996744 PC3 12800 8-8-8-24
- Comparison Module #6: G.Skill ECO series
- Comparison Module #7: Memonex TOP Series PC3 12800 2x2GB
CPU-Z: This application shows us the settings that we have chosen in the BIOS. Items shown in this application include CPU speed and bus settings, motherboard manufacturer, BIOS revisions, memory timings, and SPD chip information.
Task Manager: We use this utility to show physical memory, kernel memory, page file, and processor usage.
- Processor: Intel Core i7 875 208x21
- Memory: Patriot PC3 20000 2490MHz 8-11-8-27
This set of memory was qualified using ASUS' P7P55D motherboard so that's where my testing started. Try as I might, anything over 2508MHz was not going to happen with this CPU under air or water. Just getting to 2500MHz means this is the fastest set of memory tested here at OCC. Upping the Cas latency TRCD and TRAS and voltage well beyond what should be safe, did not give any measurable gains stable enough to pass Memtest. Seeing how this might be a limitation of the CPU or motherboard, I switched to the ASUS Maximus III Formula to validate the results. Still I had the 2508MHz limit.
So what's left? Seeing what they will do at lower speeds with tighter timings. For this testing I kept the memory voltage in the 1.65 to 1.75 volt range as set in the BIOS and adjusted the QPI voltage and vDIMM as necessary. Cas 6 was limited to 1960MHz running at 6-9-6-24. Cas 7 maxed out at 2058MHz, yet Cas 8 was able to push all the way to 2490MHz at 8-11-27. At each limit, there was a hard line that more QPI or memory voltage did not help. At this limit I would lose 1 module and only show 2GB of memory at boot and in Memtest.
Normally for the overclocking testing, I like to show the modules running as high a clock speed as possible, with the CPU down-clocked to as close to the rated frequency to minimize the increase in performance from just clock speed alone. Seeing how these modules were already at the limit of my hardware, I ran the clock speeds up as high as they would go at Cas 8 and pushed the CPU to its highest stable clock speed as an alternative to showing similar results. The Cas 8 scores at 2490 were similar enough to the Cas 9 results, that the results would not show off the capabilities of the modules. Where they do show off their ability, is in the Batman testing. When I ran the Intel Core i7 875 in this test for the review, the memory speed was just over 1800MHz using timings of 7-9-7-24. At 4392MHz on the CPU and the 1800MHz clock speed, the 875 delivered 369FPS. At a lower clock speed and higher memory speed of 2490MHz 9-11-9-27, I reached 391FPS. More memory bandwidth, does indeed help.
The maximum memory speed for each set of modules when overclocked is a measure of how well the modules ran on these particular modules and test system. As such, your results may differ in either a positive or negative way based on the capabilities of your hardware. That said, your mileage may vary!
The benchmarks used in this review include the following:
- CPU-Z Version 1.54
- Windows Task Manager
- PCMark Vantage
- Geekbench 2.1
- Super Pi 1.5
- SiSoft Sandra 2010
- Batman Arkham Asylum