To: Don Green who wrote (86064 ) 5/17/2003 7:25:28 PM From: Don Green Respond to of 93625 Rambus: One More Hurrah Can the new RDRAM chipset from SiS embarrass Intel's DDR initiative? From the June 2003 issue OF MAXIMUM PC Pg# 56 dg> See May 2003 for earlier Rambus comments Message 18853556 Rambus: One More Hurrah Can the new RDRAM chipset from SiS embarrass Intel's DDR initiative? As we reported in last month's "System Bus 800" story, Intel has rescinded RDRAM's "most favored memory technology" status, and will for the foreseeable future exclusively support dual channel DDR in its new high-performance desktop chipsets. This spells the end of Rambus-lovin' at Intel HQ but RDRAM hasn't been completely abandoned by industry players. This month, we got a chance to benchmark SiS's new R658 chipset, which joins the Intel 820, 840, 850, 850E, and 860 chipsets in the RDRAM pool of users. The R658 officially supports 400MHz and 533MHz bus-speed CPUs, up to 2GB of memory, and AGP 8x. But can it hold its own against the new Intel 875P, which supports dual-channel DDR400? Our experience with the SiS R658 came by way of Abit's S17 motherboard, which exposes a ton of memory tweaking options that we've never seen in any 850 or 850E RDRAM mobo. And like Asus' odd duck P4T533 board (not to be confused with the P4T533C), the Abit S17 board uses RIMM4200 technology. RIMM4200 (and the slower RIMM3200 technology) shoehorns two PC1066 modules into a single memory stick. This eliminates the necessity of running sticks in pairs, and helps cut down on extraneous circuitry runs. The Abit SI7 we tested featured an early engineering BIOS, but Rambus felt that the board was worthy of benchmarking. We fitted the S17 with an ATI Radeon 9700 Pro, a Western Digital WD1200JB hard drive, and 512MB of PC1066 RDRAM, and loaded it with Windows XP Pro and Service Pack 1. All the other boards tested the SiS R658 chipset will be offered exclusively in Abit's SI7 motherboard s received the same load-out of hardware, though memory types of course differed. When all the CPU fans had spun down, the SiS R658 was left wearing the stupid cap. Even though it's a modern chipset (and a full year younger the 850E, Intel's reliable RDRAM warhorse), it still came in dead-ass last in every test we ran. It ever trailed SiS’s own R655 dual-channel DDR chipset, which we tested with both DDR333 and DDR400 memory. Driver and BIOS issues could explain why the R658 did so poorly, but it's also possible that the chipset just isn't any good. With last-place performance that puts it in a class with Intel's DDR266 E7205 chipset, we don't expect much interest in the SiS R658. It requires the extremely rare RIMM4200 modules and doesn't offer any competitive edge over Intel's RDRAM chipsets. That said, RDRAM fans shouldn't start taking down the party decorations just yet. We suspected SiS is treating the R658 chipset as a proof of concept of sorts. The real day of reckoning for RDRAM on the desktop will be when SiS releases the R659 sometime this fall. The R659 will be a quad-channel RDRAM chipset that may give dual-channel DDR400 any possibly even DDR-II a run for the money.