Conclusions and Opening Thoughts
With a peak unidirectional bandwidth of 10 Gbps, the Thunderbolt interconnect offers up to 1.25 GB/s of bandwidth for attached devices. Even though this is the first generation – and the first implementation on the PC – I am impressed with what we were able to demonstrate in our time with the ASUS P8Z77-V Premium motherboard and the Pegasus R4 external RAID device. With default settings and the set of four 1TB hard drives, we were able to hit 493 MB/s read speed in RAID 5 and just over 700 MB/s read speed using a RAID 0 configuration. That is pretty nice and directly rivals performance for internal, PCIe based or on-board devices.
Using the set of four Corsair Force GT 120GB SSDs in the same R4 device, we found the maximum performance level of about 930 MB/s – not quite up to the 1+ GB/s I was hoping for but with transfer overhead and early hardware/software, I think I'll take it. Seeing this level of performance from external devices that are relatively low cost (relative to other professional products that is) can really start to change the way we connect PCs and devices.
The biggest feature of Thunderbolt is obviously the ability to daisy chain and to include a display on the connection as well. In our daisy chaining test we were able to get a pair of Pegasus R4 devices to work perfectly together and scale performance near that 900+ MB/s limit we were hitting with the SSDs.
The Apple Thunderbolt Display, though overpriced for its size and features, is a great example of a device that can be implemented with Thunderbolt to offer a fantastic user experience. Yes, the 27-inch 2560×1440 panel is impressive on its own, but the single Thunderbolt connection that provides the display signal as well as providing data connections for the USB, FireWire and Ethernet ports will make for easy portability and expandability for notebooks. Not only that, but a proper Thunderbolt pass through enables you to expand to even more devices – though not another display.
Because standard monitors are supported with basic DisplayPort connections, Thunderbolt's capability to stream both a display connection as well as up to 6 data devices will allow users and system integrators a lot of options. Just keep in mind that each Thunderbolt port can only support a single display, whether it is a DisplayPort monitor or a Thunderbolt monitor.
More Than Storage
Though we have focused on Thunderbolt as a storage technology in this article simply because that is the where the accessories are at today, the truth is that the differences between Thunderbolt and USB 3.0 are pretty dramatic. We have already seen some devices like the MSI GUS II that offers an external discrete graphics dock through a Thunderbolt connection. Because TB is an extension of the PCI Express bus, many of these types of devices will be developed in the coming months and we fully expect Thunderbolt to change the landscape of external infrastructure.
ASUS P8Z77-V Premium
As our first motherboard and platform for Windows to integrate Thunderbolt, the ASUS P8Z77-V Premium motherboard has been a dream to work with. Integrating the Cactus Ridge controller and spending a lot of time teach us the "how" and "why" for certain design decisions has certainly enlightened me to the demands on engineers with next ultra-high speed interconnects.
Besides the obvious Thunderbolt feature that the ASUS Premium board offers, there is a lot more cool tech to be found on it. It is one of the (very) few Z77 motherboards to integrate a PCIe Gen 3.0 PLX chip for 32 lanes of PCIe 3.0 bandwidth as opposed to the 16 lanes provided by the Ivy Bridge processor itself. This allows ASUS to offer support for 4-Way SLI and CrossFire configurations with each slot getting a x8 PCIe 3.0 connection.
You will also find an mSATA port for SSDs and in our case, a 32GB SSD included for caching right away. ASUS is also unveiling a new "SSD Cache II" feature that allows you to use an SSD of any size for caching purposes, and even to combine multiple SSDs for a single cache – something Intel's RST doesn't offer. Dual-band WiFi is on-board too.
Closing / Opening Thoughts
When Thunderbolt was first released on the market, many wondered if the technology was going to be able to win out against the ubiquity of USB 3.0. After spending a lot of quality time with the first round of Thunderbolt hardware I believe that both technologies could likely co-exist for quite some time as both have advantages. USB 3.0 is significantly cheaper to integrate (both in terms of board design and controller IC cost) enabling more platforms to integrate it on-board and for more accessories and devices to ship out to consumers. Thunderbolt is expensive, reportedly adding $30 to the build cost of a motherboard today. That is a LOT for a single port of connectivity that ASUS can't even be sure will be utilized by the consumer. Not to mention the $50 cable required for each device (though this could be going down over the next several months).
Thunderbolt offers twice the available bandwidth as USB 3.0 and will likely ramp up its speed as more controllers come down the pipeline from Intel. Thunderbolt's ability to daisy chain devices and share a single port also allows it to find its way into Ultrabooks and tablets while still providing the same capability as several USB 3.0 ports would require, without the need for any kind of hub. Having DisplayPort connectivity built in allows users to utilize Thunderbolt as a dual-purpose connection without requiring some kind of display controller like current USB 3.0 display devices do.
The real question is whether or not users will adopt Thunderbolt as they have adopted USB 3.0? Maybe, but to be useful to the average consumer, there will need to be more devices that implement the technology – including external drives and docks (like this one from Seagate), monitors and expansion hubs. And they need to be cheaper. I really enjoyed my time with the Pegasus R4 but it will cost you at least $1100 to get your hands on one with four 1TB hard drives. Much of this is simply a result of the pro-sumer nature of early Thunderbolt adopters and I'll be curious to see how quickly these prices come down.
Thunderbolt has made a believer out of me, however that is only if you have a specific workload that will take advantage of this kind of transfer speed. In the near future it may well, in fact, become a standard for devices like displays and external drives. For now, only users that work in these kinds of professional level applications need to spend the money. We'll be back soon to test out the ASUS ThunderboltEX add-on card for their Z77 line of motherboards and make sure that the performance and experience remains just as pleasant.
Gold Award for ASUS P8Z77-V Premium
Editor's Note: In a completely different vein, we talked with ASUS' JJ Guerrero last month about their Thunderbolt integration on the P8Z77-V Premium. If you want a brief overview of the technology and some quick performance numbers from ASUS, check out the video below!