Intel's Z68 Express: Sandy Bridge-Tailored Core Logic With SSD Finesse

Back prior to the start of CES 2011, my Intel Sandy Bridge processor coverage focused primarily on the CPU architecture, admittedly giving comparative short shrift to the companion ‘Cougar Point’ H67 Express and P67 Express chipsets. A glance at the respective system block diagrams:

will reveal one reason for my lack of chipset enthusiasm; although they derive from a common silicon foundation, Intel selectively enabled a mishmash of features intended to distinguish them but instead likely to confuse potential implementers and end users alike. H67 Express provided access to the on-CPU graphics core, along with the ability to overclock it, but didn’t allow for CPU or system memory over-clocking. P67 Express was the converse, enabling enthusiast-friendly processor and DRAM clock boosting but sidestepping the on-CPU GPU.

At first glance, such differentiation might not seem ill-conceived; after all, PC power users prone to system overclocking are also going to yearn for high-powered discrete graphics cards. But not only did P67 Express block access to the processor’s integrated graphics, it also precluded use of a far more valuable on-CPU function block, the Quick Sync media processing core leveraged for hardware-accelerated video decoding, encoding, transcoding and other processing functions. And then the chipsets’ 6 Gbps SATA bug reared its ugly head, further squelching designers’ enthusiasm to migrate to the Intel Sandy Bridge platform generation.

That artificial distinction is dissolved with the successor Z68 Express ‘Panther Point’ chipset, unveiled today:

Motherboard and system designers among you can, if you choose, craft implementations that enable CPU and system memory overclocking (along with correspondingly raising the allowable current, voltage and power consumption thresholds) while simultaneously leveraging (and clock-boosting, to boot) the cost-effective on-CPU graphics core. And even if you prefer to get your graphics ‘fix’ over a PCI Express bus (or few), you can still (as was also the case on H67 Express) harness LucidLogix’ Virtu software technology to tap into Sandy Bridge’s Quick Sync media acceleration capabilities. LucidLogix may be familiar to some of you from its previously announced HydraLogix IC, which synergistically mates otherwise dissimilar graphics chips (and integrated chipset cores) from multiple vendors.

If the merging of H67 Express and P67 Express capabilities were all that Z68 Express offered, I admittedly wouldn’t be particularly enthused about ‘Panther Point’. But Intel’s got one additional trick up its sleeve. No, it’s not native USB v3 support; it looks like we’ll need to wait for that particular Thunderbolt competitor-or-not until the 22 nm Ivy Bridge CPUs’ ‘Panther Point’ chipset. Instead, Intel will augment its Rapid Storage Technology drivers (which historically enabled features such as RAID 0/1/5/10 support) to enable an in-system SSD to act as a high-performance front-end cache for a much larger HDD.

Smart Response Technology (formerly SSD Caching), as Intel brands the technique, is conceptually ‘old news’. The company (to some extent in partnership with Microsoft) has been promoting the ‘Turbo Memory’ concept for many years; the ‘Robson’ project targeted Windows Vista and leveraged the ReadyBoost technology built into that particular O/S. The ‘Braidwood’ successor was more O/S-agnostic and, taking advantage of falling semiconductor costs, beefed up the amount of flash memory devoted to the effort. And a discrete ‘Turbo Memory’ subsystem offers some notable advantages over the hybrid HDD alternative, which embeds a flash memory cache within the rotating storage device. Systems OEMs aren’t restricted to single-source specialized HDDs, for example, and they can also selectively include or exclude the flash memory module in differentiating between cost- and performance-optimized system variants.

However, ‘Turbo Memory’ implementations have to date employed simplistic flash memory single- or multi-component arrays mounted on PCI Express Mini Cards and the like, thereby necessitating system CPU-based flash memory media management algorithms that are O/S-specific and therefore difficult to both develop and maintain. With Smart Response Technology, Intel instead leverages conventional SSDs as caches (up to 64 GBytes’ worth; if the SSD is larger than that, the remainder can be configured as a separate partition with unique drive letter). While managing data flow between the SSD and HDD (conceptually comparable to RAID media management routines) remains the responsibility of O/S-specific high-level drivers, the low-level flash memory media management algorithms (by far the harder nut to crack) are instead handled by the on-SSD controller.

I’ll wrap up this particular writeup with an ironic wrinkle. While Intel didn’t allow the tech press to talk about ‘Panther Point’ until now, most-favored systems partner Apple has been selling Z68 Express-based iMacs for more than a week, as my buddies at iFixit discovered via a product teardown. Apple offers Sandy Bridge iMac variants containing HDDs, SSDs and HDD-plus-SSD combos. In the latter case, it doesn’t seem that Apple leverages Smart Response Technology, which would present the HDD-plus-SSD combo as a single drive to the operating system. The company has, however, seemingly still made a notable O/S enhancement.

Mac OS X and its applications, along with any particular user’s data directory structure, have historically by default all resided on a single drive or RAID’d drive array. Separating user data from its associated apps has been at best extremely difficult to accomplish, if not impossible, and left to users to negotiate. Now, however, Apple’s sales documentation states:

If you configure your iMac with both the solid-state drive and a Serial ATA hard drive, it will come preformatted with Mac OS X and all your applications on the solid-state drive. Then you can use the hard drive for videos, photos, and other files.

SSD-inclusive iMacs aren’t yet shipping, so I don’t yet know how literally to take Apple’s vague wording. I also don’t yet know if, via Apple’s Boot Camp dual-boot utility and drivers, it’ll be possible to harness Smart Response Technology on Windows even if it’s not (yet) available on Mac OS X.

The Z68 Express chipset costs $48 in 1,000-unit quantities. Also in production is the company’s ‘Larsen Creek’ 311 Series of SSDs, intended for Smart Response Technology applications and available in 2.5″ SATA and m-SATA (mini-SATA) form factors:

The 311 Series is a 34 nm high reliability, fast-writing SLC (single level cell) flash memory-based variant of the earlier-announced 310 (mini-SATA) and X25-M (SATA) product lines. 20 GByte 311 Series SSDs cost $110 (1,000).

My Intel-branded, Z68 Express-based motherboard should be arriving in a few weeks, so stay tuned for benchmarks. Until then, content yourself with AnandTech’s hands-on chipset and third-party motherboard reviews.