PCMark05: CPU and Memory
For our next round of synthetic benchmarks, we ran the CPU and Memory performance modules built into Futuremark's PCMark05 suite. The following tests are synthetic benchmarks designed to show relative performance metrics but may or may not equate to "real-world" performance.
"The CPU test suite is a collection of tests that are run to isolate the performance of the CPU. The CPU Test Suite also includes multithreading: two of the test scenarios are run multithreaded; the other including two simultaneous tests and the other running four tests simultaneously. The remaining six tests are run single threaded. Operations include, File Compression/Decompression, Encryption/Decryption, Image Decompression, and Audio Compression" - Courtesy FutureMark Corp.
The CPU performance module test shows the Core 2 Extreme QX6850 ahead of its 1066MHz FSB-based quad-core brethren, the QX6800 on the 975x chipset, by about 7% - that lead is much smaller when testing the QX6800 on the P35 chipset, however. Even though the two processors have nearly the same core frequency (2.93GHz for the QX6800 and an even 3GHz for the QX6850), the additional front side bus bandwidth of the QX6850 in conjunction with the newer chipset give it a more significant advantage in this test.
"The Memory test suite is a collection of tests that isolate the performance of the memory subsystem. The memory subsystem consists of various devices on the PC. This includes the main memory, the CPU internal cache (known as the L1 cache) and the external cache (known as the L2 cache). As it is difficult to find applications that only stress the memory, we explicitly developed a set of tests geared for this purpose. The tests are written in C++ and assembly. They include: Reading data blocks from memory, Writing data blocks to memory performing copy operations on data blocks, random access to data items and latency testing." - Courtesy FutureMark Corp.
The inherent nature of Intel's current quad-core architecture requires all cores on the chip to share a single system bus. As a result, we actually see memory bandwidth on in the PCMark Memory performance module scale in favor slightly of the dual architectures, when you compare scores between the QX6800 and X6800, for example. However, the new QX6850's extra FSB bandwidth at 1,333MHz compensates for this nicely. As a result, the QX6850 is able to boast a 4% advantage over a similarly clocked X6800 dual-core processor and a roughly a 8-10% advantage over a QX6800 quad-core CPU.