If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
A7N8X Deluxe...Asus says it DOES support 150Mhz with it's onboard serial ATA..are they lying?
A7N8X Deluxe...Asus says it DOES support 150Mhz with it's onboard
serial ATA. I've heard that the serial ATA on the A7N8X Deluxe runs thru the PCI, and is therefore limited to 133....but Asus says no to that...? http://www.asus.com/support/faq/qanda.aspx?KB_ID=82959 |
#2
|
|||
|
|||
John Q. Public wrote:
A7N8X Deluxe...Asus says it DOES support 150Mhz with it's onboard serial ATA. I've heard that the serial ATA on the A7N8X Deluxe runs thru the PCI, and is therefore limited to 133....but Asus says no to that...? http://www.asus.com/support/faq/qanda.aspx?KB_ID=82959 The FAQ states is spports 150MB/s... between the SATA controller and the hard drive. PCI is still clocked as usual. Damien |
#3
|
|||
|
|||
In article , John Q. Public
wrote: A7N8X Deluxe...Asus says it DOES support 150Mhz with it's onboard serial ATA. I've heard that the serial ATA on the A7N8X Deluxe runs thru the PCI, and is therefore limited to 133....but Asus says no to that...? http://www.asus.com/support/faq/qanda.aspx?KB_ID=82959 Sometimes I don't know why Asus bothers with the FAQ page... SATA performance has the following limits: 1) Media head rate - Raptor is 70MB/sec and is the fastest I know of. 2) Drive can have a RAM cache. Depending on where this sits (before or after bridge), it can absorb the full data rate for short intervals. 3) Drive uses IDE/SATA bridge chip - this is limited to 100MB/sec or 133MB/sec. I don't know if there are any native hard drives yet or not. 4) Cable rate is 150MB/sec and this is fixed. The cable actually runs at 1500Mbits/sec, and is 8B10B coded. The coding reduces the usable data rate to 1500*(8/10) = 1200Mbits/sec and this is the stated 150MB/sec. I haven't read the whole spec, but it is possible fewer symbols per second could be sent if flag symbols (like JK or K28.5 are sent) are used to take the place of data. 5) The SIL3112 has FIFO buffers inside the chip, which makes it possible for the chip to absorb data at full speed (150MB/sec) for very short intervals, from the SATA cable. I don't know how flow control is achieved or whether flow control results from limiting the size of data chunks used for transfers. 6) The PCI bus has a theoretical burst rate of 133MB/sec for the 32bit 33MHz version of PCI. When using reasonably short data bursts on the bus, about 100MB/sec will be achieved. But the SIL3112 datasheet says the chip can be clocked at 33MHz or 66MHz. It is unlikely a desktop motherboard would have something faster than 32bit 33MHz for the PCI bus, so the 66MHz option is extremely unlikely. (I would need Nvidia documentation to be sure and they don't give it out.) After all that mumbo-jumbo, most people will find bursting of less than 100MB/sec for short intervals, is their limit. This limit can be in several places, as stated above. Higher than 100MB/sec has been achieved. Someone benched the Intel SATA RAID on the ICH5R, and because the bus connection inside the ICH5R is 266MB/sec, faster than 100MB/sec is possible (with two Raptors in RAID mode). I've also read comments recently from someone who has compared the same IDE drive with and without a SATA adapter connected to it. He finds the SATA way is slower, and this could be due to the protocol overhead for sending commands to the drive. But until you have seen several people try this experiment with different brands of drives and PATA/SATA adapters, don't take this suggestion as gospel. HTH, Paul |
#4
|
|||
|
|||
SATA has a maximum speed of 150MB/s
PCI has a maximum spped of 133MB/s SATA has a MHz value of 1500 PCI has a Mhz value of 33 it is all to do with the number of bits moved in each cycle. for SATA, this is 1 for PCI, this is 32. I currently ignore PCI-X or similar as they are not common. For reference, the better PCI found on server boards is 66Mhz, 64bit per cycle for a total of 533MB/s and if you would like, think back to the old ISA format, 8Mhz and 16bits (if I recall correctly). These speed limits are are expected to be around for along time, at least until the newer PCI standard comes more common A On Mon, 30 Aug 2004 22:48:39 -0400, John Q. Public wrote: A7N8X Deluxe...Asus says it DOES support 150Mhz with it's onboard serial ATA. I've heard that the serial ATA on the A7N8X Deluxe runs thru the PCI, and is therefore limited to 133....but Asus says no to that...? http://www.asus.com/support/faq/qanda.aspx?KB_ID=82959 |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
asus A7N8X deluxe & win98 | CU | Asus Motherboards | 1 | May 27th 04 05:18 PM |
Asus A7N8X Deluxe Motherboard | [email protected] | General | 4 | December 19th 03 01:54 PM |
Asus A7N8X Deluxe or Abit NF7-S Which? Choosing a MB. | James Paraskeva | Overclocking AMD Processors | 11 | November 26th 03 06:16 PM |
Asus A7N8X Deluxe mobo and Thermaltake Xaser III case cables | Andrew Crook | Homebuilt PC's | 1 | July 11th 03 04:50 PM |
Random reboot on asus a7n8x deluxe | Bob | Overclocking AMD Processors | 2 | June 24th 03 09:51 PM |