18:03
Laptop Trouble Tips
The new Marvell chip was due to launch with Intel's P55 chipset, but was pushed back because of firmware/software issues we were told, not to mention the fact that Seagate's hard drive wasn't ready for public release until later this month. These issues have apparently been fixed since the revamped set of SATA 6Gbps enabled boards are starting to trickle out from motherboard manufacturers like Asus and Gigabyte.
The Marvell SATA 6Gbps chip on both the Asus (left) and Gigabyte (right) motherboards
Inside the 88S9128/3 Marvell has crammed two SATA 6Gbps sockets and a legacy ATA133 parallel port since hardware manufacturers still request it, although it can obviously be ignored. In addition to this there's "hardware" RAID 0 and 1 on the "8" but not the "3" which Asus uses. It's all connected via a single PCI-Express x1 2.0 lane as well.
The bandwidth is key to this chipset, and supporting PCIe 2.0 allows a "true" SATA 6Gbps bandwidth. We say "true" because even the 500MB/s from a Gen 2.0 PCI-Express x1 lane is only 65 per cent of the theoretical maximum 768MB/s enabled by the new standard. If we bolt the Marvell chip directly onto a P55 chipset, it gets Gen 1.1 bandwidth (as Intel claims P55 is Gen 2.0 "compatible", which it needs to be anyway to adhere to the PCI-Express standard), offering only one third the bandwidth potential: a clear bottleneck. In fact, current SATA 3Gbps chipsets saturate a Gen 1.1 PCI-Express x1 bus in the same way: with a 384MB/s SATA standard forced through a 250MB/s bus.
The Marvell SATA 6Gbps chip on both the Asus (left) and Gigabyte (right) motherboards
Inside the 88S9128/3 Marvell has crammed two SATA 6Gbps sockets and a legacy ATA133 parallel port since hardware manufacturers still request it, although it can obviously be ignored. In addition to this there's "hardware" RAID 0 and 1 on the "8" but not the "3" which Asus uses. It's all connected via a single PCI-Express x1 2.0 lane as well.
The bandwidth is key to this chipset, and supporting PCIe 2.0 allows a "true" SATA 6Gbps bandwidth. We say "true" because even the 500MB/s from a Gen 2.0 PCI-Express x1 lane is only 65 per cent of the theoretical maximum 768MB/s enabled by the new standard. If we bolt the Marvell chip directly onto a P55 chipset, it gets Gen 1.1 bandwidth (as Intel claims P55 is Gen 2.0 "compatible", which it needs to be anyway to adhere to the PCI-Express standard), offering only one third the bandwidth potential: a clear bottleneck. In fact, current SATA 3Gbps chipsets saturate a Gen 1.1 PCI-Express x1 bus in the same way: with a 384MB/s SATA standard forced through a 250MB/s bus.
0 comments:
Post a Comment