By just looking at memory bandwidth it is hard to judge the performance of any platform, other factors come into play when you look at the overall performance. To be able to determine if the i845 is able to deliver under simulated real-world conditions weíve used SYSmark 2001 to compare both chipsets. To see how well the chipset scales weíll be running the same benchmark suite on a 1.5 and a 2.0GHz Pentium 4 CPU.
Fig 7. The SYSmark 2001 benchmark results paint a very clear picture, even a 2GHz Pentium 4 isnít able to surpass a 1.5GHz using the i850-chipset.
It needs no further explanation that the i845 isnít to be considered a viable alternative to i850 at all when running office applications. If we look at the SYSmark 2001 results once more in terms of % increase, or decrease, in performance we find the following:
SYSmark 2001, 1.5GHz: (i850/i845) x 100% = (157/135) x 100% =
SYSmark 2001, 2GHz: (i850/i845) x 100% = (182/148) x 100% =
The SYSmark 2001 benchmark clearly shows that the i845 lags behind, at 1.5GHz clockspeed the i850 is 16% faster and at 2Ghz the gap widens to 23%. Even when using a 2GHz Pentium 4 the i845-chipset isnít able to come close to a 1.5GHz Pentium 4 running on the i850-chipset with dual channel RDRAM. One other thing that can be read from these benchmark results is the fact that the i845 doesn't scale too well with clockspeed. Just look at the following:
SYSmark 2001, i850: (2GHz/1.5GHz) x 100% = (182/157) x 100% =
SYSmark 2001, i845: (2GHz/1.5GHz) x 100% = (148/135) x 100% =
As derived from the results above, an increase in clockspeed of 500MHz yields a 16% increase in performance for the i850-chipset, whereas the i845 only offers a 10% increase. Thus the i850-chipset plaform scales much better with clockspeed than the i845, courtesy of its high-bandwidth memory bus. The bandwidth offered by the PC133 SDRAM really limits the performance of the Pentium 4 at higher clockspeed. We expect to see even worse results when the clockspeed ramps up over 2GHz.