Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933273AbZJNTr2 (ORCPT ); Wed, 14 Oct 2009 15:47:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759710AbZJNTr1 (ORCPT ); Wed, 14 Oct 2009 15:47:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21697 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759525AbZJNTrZ (ORCPT ); Wed, 14 Oct 2009 15:47:25 -0400 Message-ID: <4AD62B52.9060200@redhat.com> Date: Wed, 14 Oct 2009 15:49:38 -0400 From: Don Dutile Reply-To: ddutile@redhat.com User-Agent: Thunderbird 2.0.0.18 (X11/20081113) MIME-Version: 1.0 To: Krzysztof Halasa CC: Stefan Assmann , Linux Kernel Mailing List , Jesse Barnes , kaneshige.kenji@jp.fujitsu.com, matthew@wil.cx Subject: Re: GT/s vs Gbps for PCIe bus speed References: <4AD58EEE.4070405@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1604 Lines: 47 Krzysztof Halasa wrote: > Stefan Assmann 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 ... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/