"HP DC7900 CMT: the Good, the Bad and the Ugly. A User Review"

By Ron Stultz

7 April 2016

Summary: older HP business workstation that supports Windows 10 at a reasonable cost. But do not touch if you are not familiar with driver installation, adding hard drives, updating Windows off the Internet, etc.

Background:

Resisted upgrading from Windows XP.

In last couple of months, Google Chrome began telling me it would no longer support XP and then Turbotax said 2016 version would not run on XP. Sooooooo......time to upgrade.

Tested XP machine and hardware does not support Windows 10.

Could have upgraded to Windows 7 but would have to reinstall all programs, so why when free upgrade to Windows 10 from Microsoft.

Did not want to spend $500 or more for off-the-shelf Windows 10 machine.

Run RAID D: drive with all personal files, so need machine that supports PCI and 3 hard drives.

As I add and subtract hardware as needed, prefer more space inside enclosure over tight.

eBay search:. HP DC7900 convertible mini tower (CMT) with Windows 7 Pro installed, 4GB of memory and 1TB hardrive, $120.

As not all machines running Windows 7 can run Windows 10. Took a chance.

The one I bought is the CMT and features on the other 2 models of DC9700 are smaller and have less of everything. I personally would not buy anything but the CMT model.

The Good:

A lot of these coming off lease and available.  Would only buy CMT model with at least 4GB of memory and Windows 7 or 8 installed.

The DC7900 was manufactured around 2011 and from examination, all capacitors appear to be fine. (Age and heat has a way of distroying the small round cylinders sticking up off the motherboard resulting in erratic behavior sometimes.)

Be aware that simply having Windows 7 installed does not mean all HP board specific drivers have been installed. There were no drivers installed on my eBay machine.

All HP drivers for the DC7900 are available from HP download website. Up might have to download the Ethernet driver first on a different computer, moved to USB drive and then install on DC7900 via USB. Once Ethernet adapter going and hooked to your Internet, should be able to download and install all other HP drivers.

The dual core version I have supports Windows 10. Motherboard will support quad-core and these are available off eBay but unsure if I will ever try it or not.

Mother board uses Intel chipset and has built in: 1Gbps Ethernet; audio and graphics. 1Gbps Ethernet is nice because many current off-the-shelf computers do not have this and on XP I had to use add-on board for 1Gbps.

Motherboard supports RAID mirror or stripped on C: drive (have not tried it)

Has 5 SATA ports on motherboard but one is external eSATA.

Unsure of board SATA speed but probably at least 3Gbps. Do not know if auto negotiate speed or not.

Has 2 PCIe slots.

Has 3 PCI slots.

Has easy to remove, massive cooling heatsink with fan on CPU chip and air diversion cover ensures good CPU cooling.

Has easy to remove, good size, heatsink on video chip.

Large physical size, 300watt power supply (See Bad).

Has 5 USB ports to include 2 on the front panel. USB is version 2.

Has 4 memory module slots and will hold 16GB of Ram. Ram is PC6400. (See Ugly).

Will hold 2 hard drives in front bay, plus CD-DVD drive.

Will hold 2 drives at bottom of front bay. Location of C: drive.

Has built-in chassis fan just below power supply on back panel. Motherboard adjustable speed.

The eBay specific I bought came with 1GB hard drive but have seen offerings vary on size of drive installed. For C: drive 250GB is sufficient if you going to add a D: drive.

Has motherboard connectors for both serial and parallel outputs. My eBay came with a parallel installed which I removed.

BIOS is not the most robust I have seen in the way of settings but has many to include some for management purposes I have never seen on a consumer-model personal computer.

The Bad:

No IDE ports, must connect SATA drives.

No AGP slot so no using older AGP video cards.

Hard drive installation in front bays a little tricky as must slide into well defined slots in chassis.

Must remove front panel to do any work on chassis hard drive bays.

Very unclear about dual channel memory. Appears that it might support but not certain and motherboard at BIOS does not clearly call out hyper-threading.

Onboard audio is nothing to write home about but works decently with little in the way of adjustments possible.

Power supply is non-standard in size. As I always use 500-750 watt power supplies, had to modify chassis to support 500 watt I installed. Do see that the power supply for the DC9700 CMT is readily available off eBay and not expensive. Assume HP power supply, because of size, was a good quality power supply to ensure limited problems for HP while on lease.

The Ugly:

Supports up to 16GB of memory but 4GB modules for this are quite expensive at $65+ each. I upgraded to 8GB by buying (4) 2GB modules. Maybe $40 for all.

Apparently standard model sold into businesses only had 4GB of memory or (4) 1GB modules and is insufficient to properly run Windows 10. Must have at least 8GB with cheapest way is (4) 2GB modules.

Onboard video eats into installed memory module memory, reducing what's available to Windows 10 and thus really needs a PCIe or PCI video card installed. I did a cheap, 1Gb onboard memory, video card.

What I did:

Replaced all SATA cables and power connectors with those that have a retainer clip. Many problems over the years related to loose SATA or SATA power connectors.

Removed heatsink off CPU and video chip, cleaned all surfaces and renewed thermal past and reattached heatsinks.

Installed all HP drivers.

Installed my RAID card and driver and got my RAID going again.

Hooked to Internet and downloaded all Microsoft updates for Windows 7 Pro. This took hours and hours because almost 800MB of updates. And once one set of updates installed, had to check again and again to ensure there were not any more.

With Windows 7 fully updated, downloaded free Windows 10 Pro and installed. Recommend that you not try to upgrade to Windows 10 until your existing OS is fully upgraded

Installed 1GB video card on PCie slot.

Don't like Windows 7, 8, 10 start menu so installed "Class Shell" which is a free program that gives me a classic XP menu.

Once Classic Shell installed, configured it and then moved programs from program start menu to various functional "folders" on my Classic Shell menu.

Now checked for Windows 10 updates and had to download many.

Downloaded and installed latest Windows Media Player.

Replaced BIOS battery.

Installed Microsoft Office and then downloaded all updates from Microsoft.

Installed all my other programs.

Downloaded and installed "Gary Utilities" which is a free, multi-function tool for windows to include cleaning registry, deleting empty or temporary files, short cut problems, etc.

Downloaded and installed "Astrologics Defragger" which is a free defragger than has the option to reorganize your hard drives such that operating system files are place in the fastest access area of the disk.

Downloaded, installed and ran Microsoft's Malware remover.

Downloaded, installed and ran Microsoft's virus remover, "Defender".

As of this date, no blue screen of death or any other abnormality.

Summary:

Tthe HP DC9700 CMT can make a decent, middle of the road in terms of processing power, desktop but does require some computer expertise and patience.