Core i7 with 12 GiByte DDR3-RAM tested - benefits for GTA 4

Core i7 processors deliver an impressive gaming performance - as long as you have a graphics card that can keep the pace. And since almost every Socket 1366 motherboard has six memory slots, it's rather easy to install 6x 2 GiByte RAM. In our article we describe if twelve GiByte DDR3-RAM can deliver a benefit in games and which problems could occur.

Test system

Unfortunately we didn't have two identical Triple Channel kits available for our tests. Therefore we combined Corsair's Dominator version TR3X6G1600C8D with the Mushkin kit 998679. According to the producers both sets are supposed to run in DDR3-1600 mode with 1.65 volt. This is important because according to Intel more than 1.65 volt could be dangerous to the memory controller and the CPU. Therefore we didn't increase the voltage above that limit. For our tests we used the current top-dog Core i7-965 Extreme Edition and a Geforce GTX 285. In matters of the motherboard we had several candidates - the next paragraph explains why.

Practical problems

Good news: Six memory modules with 2,048 MiByte each worked fine on all tested motherboards (up-to-date BIOS required). Bad news: Stable DDR3-1600 mode was not possible. At first we checked the new high-end board P6T6 WS Revolution from Asus. Here the system started even with 900 MHz (DDR3-1800) but Prime95 noticed errors after a few seconds already. With high latencies of 9-9-9-24 and 2T Command Rate the DDR3-1600 mode was not stable. A possible reason for this is the mix of two different memory kits. To test this we exchanged three modules with the Triple Channel kit F3-12800CL9T-6GBNQ from G.Skill - the problem was not solved. With the seconf motherboard, Gigabyte EX58-Extreme, the system didn't start with six modules at all when we selected DDR3-1600 mode. The new Gigabyte board EX58-UD4P started but stable operation was not possible. With three modules in DDR3-1600 mode on the other hand, we didn't receive any errors in Prime95 and so we used the EX58-UD4P for our tests.



Important: If you plan to use only three DIMMs, you should install the modules into the slots that are farther away from the CPU socket. If you want to overclock the memory via the reference clock speed, you should also lower the multipliers for QPI and Uncore clock. For our tests we only adjusted the multiplier and didn't change the reference clock speed - we wanted to check the differences between individual memory frequencies and not increased CPU clock speeds after all.