<<5-15% in word,internet explorer? huh?>>
In Office applications is where memory bandwidth really shows itself, so perhaps yes. Considering how much the CPU does, even IE will benefit from the extra bandwidth.
<<I dont know if this is entirely true either. In most CPU intesive tasks DDR is on par or even better than RDRAM. But theres less memory bandwith and yet the thing still runs at full potential at its speed. I can see were the difference is when you have cpu and memory intensive tasks going on. But still sometimes some of that bandwith wont even be used or needed in those applications.>>
I've yet to see a P4 using DDR memory perform on par, let alone exceed a P4 with RDRAM, in any application. The article on Tom's Hardware points out a huge advantage between the Pentium 4 at 400fsb versus one at 533fsb, both using synchronous memory. All of the DDR articles prior to his newest article have shown a 3-5% difference in applications comparing DDR memory on VIA chipsets to RDRAM on the 850 chipset. We are talking performance at lower speed ratings of 1.5GHz, not even the 2GHz or better that an overclocked Northwood will often reach.
Well WinXP seems to be sucking up about 190MB of memory right now. Very few applications are going to fit into that tiny 512k of L2 cache, meaning my everyday applications are running from memory not cache. Sure the cache holds the immediate information, but if even 1% of that 190MB is needed then that easily exceeds that 512k cache's potential.
This means that the Pentium 4 is going to rely heavily on the memory for performance when doing realworld tasks. Benchmarks that stress memory bandwidth are often better than the 10-15% difference when considering DDR versus RDRAM. You want to know if non-memory intensive benchmarks matter whether on DDR or RDRAM. In every realworld case where memory is heavily consumed by background tasks it will matter.
<<Both the RDRAM and dual channel DDR chipsets equate to the same bandwith , which is 4.2 gb/s.>>
Interesting, but what dual-channel DDR chipset is that? So far there are no dual-channel chipsets. Are you talking VIA chipsets? Funny, but there is a shortage of motherboards out there being touted with this mythical dual-channel VIA chipset. Oh, wait - you probably meant interleaved. So from what I gather you feel interleaved equates to dual-channel. Not hardly, more like 2/3rd's of a true dual-channel. Its an improvement over plain single-channel memory, but its not the miracle worker you may think.