Navigate: Advice Beginners BIOS Guide CPUs Links Mainboards Memory Network Storage Video/Sound Cards Contact Forum SiteMap Sponsors WebNews Home	.	.
CPU Intel P4 840 D P4 820 D P4 630 P4 640 P4 650 P4 660 P4 670 AMD Athlon64 3500+ 3700+ 3800+ 4000+ X2-3800+ X2-4200+ X2-4400+ X2-4600+ X2-4800+ 1-Way Opteron Opteron 144 Opteron 146 Opteron 148 Opteron 150 Opteron 152 2-Way Opteron Opteron 240 Opteron 242 Opteron 244 Opteron 246 Opteron 248 Opteron 250 Opteron 252 2-Way Dual Core Opteron Opteron 270 Opteron 275 nVidia GF 7800GT GF 6800GT GF 6600GT ATI R X850 XT PE R X850 XT R X800 XT PE R X800 XT R X800 XL Memory Corsair Crucial Kingston Mushkin OCZ What are you shopping for?

Conclusion

In this series of benchmarks, we have systematically increased the peak memory bandwidth from 800 Mbsec to 1328 Mbsec and at the same time varied the latencies while maintaining constant CPU clock speed. Our results show that memory bandwidth increases proportionally with bus speed. Further, if latencies are shortened, moving from a 100 MHz memory bus (3:3:3) to 166 MHz (2:3:2) increases the overall transfer rate as measured by SiSoft Sandra by about 78% (CPU memory bandwidth) and 89 % (FPU memory bandwidth)

Interestingly, performance does not increase in a linear fashion with FSB frequency. On the contrary, performance increase peaks were seen at harmonic frequencies of the standard PCI frequency of 33 MHz, whereas intermediate frequencies yielded poorer performance.

Summary bar chart of selected CPU and FPU bandwidth scores (MB/sec) depending on bus frequency and latency but identical CPU clockspeed. Except for the 143 MHz memory bus, bandwidth increases almost proportional with the bus frequency.

For 3D applications such as Expendable, the increased memory bandwidth results in as much as 22.2% higher frame rates. Our findings highlight the importance of low latency, high speed memory modules, particularly in light of projected front side bus frequencies in the range of 200 MHz.

Expendable frame rates depending solely on the memory bus frequency and latency settings. All benchmarks were run at identical CPU clock speed and with identical hardware. Frame rates follow closely the FPU memory bandwidth as shown above.

The performance increase achieved by increasing the memory bus frequency and lowering latencies is roughly equivalent to upgrading from a 600 MHz to a 1 GHz PIII.

next page:    => more =>