Introduction

Setbacks with RDRAM

When we first experienced our uninspiring results with Rambus RDRAM, we tried to determine why the extra performance of the added memory bandwidth wasn't showing up in our results. We came up with several possible theories, but the most obvious were:

     (a) Our processor (in our first chipset article, 600MHz) just wasn't fast enough to really stress the memory subsystem of our Pentium III testbed. Over the following months we tested with newer chipsets and faster processors but the results mainly stayed the same, the 820 system failed to really take off. This pretty much killed this theory.

Another (of many) theory we held was much simpler:

     (b) Our benchmarks simply weren't capable of showing the benefits of the 820/RDRAM combination. We believed it would take future, more demanding, games and applications to really show the benefits of this technology.

The second theory is a tried and true excuse that has worked for many of today's now-common technologies. Therefore, it was pretty simple for us to label the 820/RDRAM system under this same category as well, despite the fact that some of our testing software (Quake III and SiSoft Sandra in particular) is very sensitive to system hardware changes and usually does a good job of highlighting the performance advantages of a given piece of technology.

History repeats itself?

Because of this, when we first received our DDR system from AMD, we weren't sure if we'd be disappointed yet again, our really see the performance potential of DDR memory and AMD's 760 chipset.

Well folks, after testing AMD's 760 system with our standard suite of benchmarks, we can easily say that our second theory was wrong. Even without overclocking, the 1.2GHz DDR system AMD sent us was the fastest setup we've ever tested.

So just what's wrong with the performance of the 820 chipset and Rambus' RDRAM? We don't know, but whatever it is, hopefully (for both companies) it's been resolved for the Pentium 4 and 850.

On to the new system…

Today, AMD launched three new processors as well as a new chipset, the aforementioned 760.

The new processors are based on the same Thunderbird core we've grown accustomed too; the new addition is a faster system bus, now up to 133MHz. Since the Athlon's bus can transfer data on both the rising and falling edges of each clock cycle (DDR), the bus effectively operates at 266MHz. This increases peak bandwidth of the bus by 33%. The new processor speeds are 1.0GHz, 1.13GHz, and 1.2GHz.