Messages in this thread | | | Date | Wed, 14 Oct 2009 15:49:38 -0400 | From | Don Dutile <> | Subject | Re: GT/s vs Gbps for PCIe bus speed |
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Krzysztof Halasa wrote: > Stefan Assmann <sassmann@redhat.com> writes: > >> IMHO this is rather confusing, as most people don't know what GT/s means. > > It's trivial to look it up, isn't it? > >> So I'd suggest the following change: >> >> --- a/drivers/pci/hotplug/pci_hotplug_core.c >> +++ b/drivers/pci/hotplug/pci_hotplug_core.c >> @@ -86,8 +86,8 @@ static char *pci_bus_speed_strings[] = { >> "66 MHz PCIX 533", /* 0x11 */ >> "100 MHz PCIX 533", /* 0x12 */ >> "133 MHz PCIX 533", /* 0x13 */ >> - "2.5 GT/s PCI-E", /* 0x14 */ >> - "5.0 GT/s PCI-E", /* 0x15 */ >> + "2.5 Gbps PCI-E", /* 0x14 */ >> + "5.0 Gbps PCI-E", /* 0x15 */ > > Isn't it like calling 100BASE-TX a 125 Mb/s? _That_ would be confusing. > BTW PCI-E can be multi-lane so Mb/s (and even MB/s) don't make sense. > I guess many people don't know what a MHz is either but we don't say > 133 MHz = 133 Mbps.
so, maybe the right terms are 2.5 GHz PCI-E 5.0 GHz PCI-E
No matter how many lanes, or how the data is sent (long or short bursts), the frequency rate is a constant.
So, the data rate is not stated, just the cycle rate. This would follow the PCIX syntax as well, which is void of bandwidth illusions.
- Don
ps -- "GT/s" isn't even defined in the PCIe spec, just blindly introduced, and unjustified in its use. ..... too much marketing-speak in PCI SIG ...
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