OCZ Z-Drive R4 C PCI Express 1.6TB SSD Review – OCZ Z-Drive R4 versus FUSION-IO ioDrive Duo

The OCZ Z-Drive R4 PCI Express SSD contains eight SandForce SF-2281 processors, 128 pieces of NAND flash memory and a Superscale Storage Controller. If ever a MONSTER storage device was created, the R4 definitely answers that call.

In fact, a simple review just doesn’t seem appropriate for the OCZ Z-Drive R4 (Z-R4).  Let’s throw it in the ring against FUSION-IO’s ioDrive Duo (io-D), see who can go all twelve rounds and emerge the true heavyweight champion.  Let the storage wars begin!


OCZs track record over the past few years shows them to be no less than a leader in SSD innovation and much of what they have accomplished has yet to be matched by their competition.  The RevoDrive line of PCI Express SSDs is a perfect example as it still has no competition for its performance and price. Currently, OCZ seems to have revamped the industries idea of what a hybrid drive should be and  will soon be releasing the RevoDrive Hybrid, capable of 910MB/s read and 810MB/s write performance.  If that weren’t enough, they  have  they have also just announced the new Synapse Cache 6Gbps SSD line which will again revolutionize the way we interact with hard drives.

OCZ continues to answer consumer demand for higher performance, yet again, by hooking the PC enthusiast (or ‘prosumer’) with the Revo 3 line and it appears that they are now setting their sites on the enterprise market with the new Z-Drive PCI Express solid state drive.

One could easily argue that they have already done that with with their RevoDrive 3×2 series that we recently reviewed, however, it seems that speeds of 1.5GB/s read,  1.25GB/s write and 200,000 IOPS at 4k aligned random disk access simply aren’t enough. The introduction of the Z-R4 sees OCZ doubling performance once again and almost appearing to ready to move in on the PCI Express SSD marketshare presently controlled by FUSION-IO.


You won’t find a publicly available price for the Z-R4 anywhere and I can add that many hours of trying to manipulate OCZ executives has met with little success as well.  The Z-R4 is an enterprise product and will be built to specifications as detailed by each customer.  OCZ will, however, be building a standard preconfigured set of Z-Drives available for immediate purchase through their enterprise distributors. We are told that direct customers can immediately meet with the OCZ Enterprise Sales Team as the Z-R4 is sampling today.

What we can say is that the Z-R4 sells for approximately $7/GB, a price less than half of that of the io-D which stands at over over $15/GB.  This can become a ‘no brainer’ for enterprise clients when they consider the ‘cost per IOP’ in comparing the Z-R4 to any PCIe or traditional rotational base storage array solution.  Now, throw in the fact that the Z-Drive is a bootable solution whereas the io-D is not and the Z-Drive takes ‘Round One’ hands down.


The Z-R4 is capable of 2.8GB/s read and write performance with 440,000 IOPS at 4k random aligned write disk access.

That’s just the beginning as OCZ can easily configure the Z-R4 with two of their Superscale Storage Controllers and double performance to 5.6GB/s read and write with 1.2 million IOPS at 4k random write aligned disk access.  Is there really a need for anything that fast?

The FUSION-IO ioDrive Duo specifications describe 1.5GB/s read and write performance with 4k random aligned write disk access of 250,000 IOPS.


The Z-R4 comes with a three year warranty and is available in several configurations to include C or R Series, half or full height form factor, eMLC, MLC or SLC NAND flash memory, as well as single or dual Superscale Storage Controllers.  Its sizes start at 300GB (depending on configuration) and stretch as high as 3.2TB.  Initial specifications describe the R Series as having Power Fail Protection and DataWrite Assurance Technology whereas the C Series does not. Our test sample is the C Series.


The Z-R4, as well as the new Revo lines, is based on SCSI (Small Computer Systems Interface) technology and is not a ‘RAID’ configuration as many seem to be stating.  Both the Z-R4 and Revo lines support TRIM, however the present Microsoft Windows Storport architecture does not support SCSI UNMAP or TRIM.  As a result, TRIM does not function in any of these drives as the commands are not generated by the OS for the Z-R4 execute.

From a personal viewpoint, TRIM has become secondary in nature and probably unnecessary, in any case, due to the excellent ‘garbage collection’ abilities we are seeing in SandForce hardware.  The initial Revo and Revo x2 lines are a perfect example, all of which still maintain excellent performance through heavy use despite their lack of TRIM.

VCA 2.0

VCA 2.0 (Virtual Controller Architecture) is OCZs ‘Crown Jewel’ so to speak and you won’t see it made available to other manufacturers any time soon.  Both the Z-R4 and Revo 3 lines contain VCA 2.0 and, similar to SandForce’s secret to SSD storage compression, this is a concept not easily explained to the average reader.  We provided a brief explanation in our RevoDrive 3×2 Review and OCZ offers a VCA FAQ Page to assist as well.