The latency of the Ram shouldn't affect the performance that much.
We have to bench similar systems with core 2 duo and xeon against to be sure.
Why don't you post some benchmarks?
It's not the latency of the RAM only. It's the latency of the whole memory subsystem. You can obviously see that CL5 and CL3 comparisons in memory latency tests do not reach 67%, it reaches only 13-15%(
http://www.xbitlabs.com/articles/cpu/display/amd-socket-am2_11.html)
Chipsets for PCs are always more configured for higher performance compared to the workstation/server chipsets which are made for better stability/flexibility.
When you see 2x the higher latency though, there's something wrong. The pattern has been that Xeons are slower per clock than the desktop equivalents since the chipsets have lower performance. One of the biggest reasons that A64 is faster than AXP is the lower latency achieved by the integrated memory controller.
So far here's the closest I can get:
Xeon 5160:
http://pc.watch.impress.co.jp/docs/2006/0801/tawada81.htm
Core 2:
http://pc.watch.impress.co.jp/docs/2006/0714/tawada79.htm
Hard to conclude on the other benches though, as most of the apps are multithreaded(except games and Business Winstone), even Cache/Memory portion of the Sandra 2007. Some of the apps tend to gain very little due to extra CPU but they do take advantage.
It shows however, Core 2 Extreme has BOTH memory and cache latency advantage.
http://www.anandtech.com/IT/showdoc.aspx?i=2772&p=4
ScienceMark didn't agree completely and reported about 65-70 ns latency on the Opteron system and 70-76 ns (230 cycles) on the Woodcrest system. We have reason to believe that Woodcrest's latency is closer to what LMBench reports: the excellent prefetchers are hiding the true latency numbers from Sciencemark. It must also be said that the measurements for the Opteron on the Opteron are only for the local memory, not the remote memory.
Core 2 Extreme got 36.75ns.
http://www.anandtech.com/showdoc.aspx?i=1884&p=11
Above we see A64 15.5% faster than AXP at Business Winstone at same clock speed. The majority of the advantage clearly lies in the integrated memory controller(there is also the advantage of doubled cache, but its a minor part of the 15.5%). The Japanese site results show 2.93GHz Core 2 Extreme performing 2% better with same hard drive than the Xeon 5160.
I don't think what I am about to summarize is a coincidence:
-SpecFP scores show 10% higher results for Core 2 Extreme against Xeon 5160(3046 vs. 2775)
-Core 2 Extreme has half the latency in Sciencemark(Anandtech)
-Core 2 Extreme only has 10% less bandwidth with HALF the memory channels compared to Xeon 5160
-Xeon 5160 achieves 3.8GB/sec(Tomshardware) with Dual Channel DDR2-533(Core 2 Extreme achieves over 5GB/sec)
-Japanese Site PCWatch tests show Xeon 5160 has nearly 40% higher latency in Everest
-Business Winstone is ever slightly faster with Core 2 Extreme, with 2% clock speed disadvantage
-The performance margins between Xeon and Opteron are somewhat narrower than Core 2 and A64/X2, Opteron has almost identical memory controller as A64 while Xeons and Core 2 has a much different one.
