IT Pro Verdict
New forces and demands are driving the eight-socket server market with virtualisation now high on the agenda. There’s currently little competition but HP’s new DL785 G5 will certainly shake things up as it offers the highest levels of internal expansion and storage capacity in a single chassis and the processor count can be easily upgraded.
It's been a while since HP dabbled in the eight-socket server market but the launch of the latest fifth generation DL785 shows it's back with a vengeance. In this exclusive review we take a closer look at a server that aims to offer more of everything. The DL785 G5 is about scalability, as along with support for up to eight quad-core Opterons, it offers masses of memory and storage expansion and a huge selection of I/O slots as well.
The DL785 targets a range of applications including databases, server consolidation and, of course, server virtualisation. Standing 7U in height, it's a chunky great box but general design is particularly good and it exhibits fine build quality.
There's a lot crammed into the front panel and the bulk of it is occupied by HP's processor memory cells. These fit into vertical bays and each contains a single processor socket and eight DIMM slots. The review system was supplied with the minimum of four cells with a large filler panel occupying the centre four bays. One upgrade step is possible where you add the other four cells but these are not hot-swappable so the server must be powered down for this particular manoeuvre.
Memory expansion is huge as HP expects to support 8GB DDR2 DIMMs giving you a top whack of 512GB. However, there is a price to pay when expanding memory. Problems caused by extra signal noise will occur when you add more than two DIMMs on each bus and to overcome this, the memory clock speed is dropped to 533MHz. If you stick with two DIMMs in each processor memory cell the clock speed steps up to 667MHz. Bear in mind this problem is not limited to HP and, so far, only IBM has overcome it where we saw in our review of its System x3755 that its XMT (Xcelerated Memory Technology) enables all its DIMMs to run at their top speed of 667MHz.
Storage options are impressive as the base system comes with one eight-drive hot-swap bay fitted, which supports compact 2.5in SFF SAS or SATA hard disks. There's plenty of room to expand as you can add a second eight-drive bay alongside using HP's option kit, which includes an extra backplane. HP's Smart Array 400i controller provides RAID as standard and supports all the usual array suspects. You can start off with a 256MB cache module and this can be upgraded to 512MB and protected with an optional battery backup unit which you'll need if you want to use dual-redundant RAID-6 arrays. There's plenty of power fault tolerance as well as the review system came with the minimum requirement of three 1,200W hot-plug supplies and there's room at the back to add three more.
