Aggressively advertising a new switch
As is often the case in the motherboard industry manufacturers are transitioning to new models of switch in preparation for Ivy Bridge. In this case it is ASrock and MSI that are the first companies to begin marketing the new switches, much as they currently market the type of capacitors they use. This has led to claims of ‘True’ and ‘Fake’ PCI-Express 3, where ‘True’ Gen 3 motherboards have the new switches, and the ‘Fake’ ones are those that support it through a BIOS update.
True and Fake may be great marketing terms, but again they aren’t completely correct. What boards with the appropriate switches do have is full x16 and dual x8 PCI-E 3 support, whereas Gigabyte’s BIOS updated boards will only do one slot of PCI-E 3 at x8 speeds. That isn’t to say all of Gigabyte’s boards have that issue – the recent G1.Sniper.2 Z68 board has the new switches so is capable of full PCI-E x16 speed.
These small switches are at the heart of the controversy.
This switching issue extends to motherboards with support for more than two graphics cards. These motherboards tend to use NVIDIA’s Nf200 chip, a remnant of its days in the chipset business. All the CPU based lanes run into the nf200, which means you don’t even get the single x8 slot coming direct from the processor. Suffice to say the nf200 lacks PCI-E 3 support, which is why you won’t see anything with more than two GPUs claiming to be PCI-E 3 ready.
This is all based upon our talks with motherboard manufacturers and the documentation supplied – as we mentioned before Intel is reticent to talk about Ivy Bridge so far from launch, and hence an official explanation is currently impossible.
To summarise what we have been able to find out about the issue – motherboards using Gen3 quick switches are capable of supporting full speed x16 PCI-Express 3 graphics cards, or multiple cards on x8 PCI-E 3 connections. Motherboards with Gen2 quick switches will only support x8 PCI-E 3 on a single card at approximately the same bandwidth that a Gen 2 x16 slot is capable of – the second slot won’t work. Any motherboard that currently supports more than two graphics cards will likely not be BIOS updateable to any PCI-Express 3 support.
After spending so much time researching the issue it is clear that everyone is at least partially correct. It is also clear that PCI-Express 3 support is largely irrelevant. There are clearly two ‘kinds’ of PCI-E 3 capability out there. The first is simple electrical capability – plug in an Ivy Bridge CPU at one end of the pipe and a PCI-E 3 GPU at the other end and you have a PCI-E 3 connection, even though it may only be eight lanes worth and only drive a single graphics card. Do the same thing with a board that has correct Gen 3 switches and you’ll have effectively the same situation except there will be a full x16 lanes worth of PCI-E 3, and you will be able to enjoy multiple graphics cards.
The former is what most Gigabyte motherboards have in terms of support. The latter is what is being done by ASrock with its ‘Gen3’ products, MSI with its (G3) branded product and Gigabyte with its G1.Sniper.2. Moving forward we expect to see the latter situation becoming more commonplace as manufacturers transition to the newer switches.
What this means for the consumer
Despite all of this we still aren’t convinced that anyone needs to care about PCI-Express 3 at the moment. We know that there won’t be a PCI-Express 3 controller on the market until Ivy Bridge, and even if it delivers a noticeable performance boost over Sandy Bridge, upgrading from one to the other is an unnecessary luxury. If you are determined to ride the crest of the early adopter wave, you’ll likely be eyeing off Sandy Bridge-E or be planning on updating your entire system, not just the CPU and GPU.
ASRock's Gen 3 motherboard is the company's new flagship product, and PCI-E 3 is a major selling point for the company.
Even then, we still haven’t heard mention of PCI-E 3 supporting GPUs yet, and even when that happens we doubt that a Single GPU would be capable of saturating the doubled bandwidth that comes with PCI-Express 3. If anything graphics card manufacturers learnt long ago that targeting a narrow sliver of the install base was an economically stupid idea – you can bet your bottom dollar that PCI-E 3 won’t be a legitimate selling point until the masses make a move to the platform. That certainly won’t happen during Ivy Bridge’s reign, and by that time we expect that all motherboards will be rocking the correct switches.
What we are left with is a marketing battle being fought over a curiosity. Credit must go to ASRock and MSI for being proactive and looking to the future with their products, and Gigabyte for actually getting a x16 PCI-E 3 capable motherboard into our hands before anyone else.
But there are many more features that we are going to judge products on, and ultimately these are the ones that an end user should care about. If you're planning on buying a system today to upgrade again early next year, and have enough faith in the GPU manufacturers to believe that there will be PCI-E 3 graphics cards as well, then you might want to pay attention to the marketing scare campaigns.
Everyone else should focus on the features that they’ll actually use, not a theoretical situation in which you spend a lot of money to do a minor upgrade. Because that is all that PCI-E 3 support currently gives you.
