HP gt7725: Hardware 

• Hardware
• Firmware
• Linux

The gt7720 and gt7725 share a common hardware base - the gt7720 running Microsoft Windows Embedded Standard 2009 whilst the gt7725 is Linux based. The one model I've seen is the gt7725 but the words here apply equally to both models.

In the photo above you can see the gt7725 both with and without the expansion unit fitted. (I think it came with a double-width foot but I can't find what I've done with it).

I don't know when the HP gt7725 (model: HSTNC-005-TC) was launched, but I've seen a 'quick specs' document dated April 2011. The first issue of the Hardware Reference Guide was in October 2008.

Physically it is the same size as the t5730. My version came with an expansion unit fitted with an additional graphics card and is referred to as the 'Quad Head Version'. Unfortunately it came with zero accessories - no PSU and no DMS-59 to dual DVI splitter for the added graphics card - not that I have four monitors to use with it!

One thing of note is that these thin clients consume a lot more power than the usual thin client. The AMD CPU fitted has a TDP of 35W. Scroll down to the photo of the internals of the gt772x and you can see that it is fitted with a fairly substantial fan in order to cool the CPU.

Specifications

Processor
Type    Speed	AMD Turion Dual Core CPU 2.3GHz
Memory
Flash    RAM	1GB 2GB (Max 4GB?)
Video (on board)
Chip    Max resolution    Connectors	AMD RS780G integrated graphics (ATI Radeon HD 3200 Graphics) 2560 x 1600 DVI-D & DVI-H
Video (expansion unit)
Chip    Max resolution    Connectors	ATI Fire MV 2250 (PCI Express x16) 1920 x 1200 DMS-59: 2 x DVI-I (via splitter cable)
Ports
Network    USB    Serial    Parallel    PS/2	10/100/1000 8 x USB2.0 1 0 2 (Kybd and Mouse)
Power
Power    Plug    Off    idle    Running	19V 4.16A (label) Coax 7.4mm/5.0mm 0W 19-24W 40W/60W
Dimensions
H x W x D (mm)	255 x 46 x 216 (Excluding Stand and expansion unit)
Security
	Kensington Lock Slot Mounting Bracket

For the gt7720 the embedded operating system is Microsoft Windows Embedded Standard 2009, whilst for the gt7725 it is Linux. However in my case it was zilch as the flash had been wiped by the seller.

As with HP thin clients of this era the hardware has two concealed USB slots under the top cover.

CPU

For those to whom it matters here is some detail from Linux's /proc/cpuinfo on the Dual Core AMD CPU.

vendor_id	:	AuthenticAMD
cpu family	:	17
model	:	3
model name	:	AMD Turion(tm) X2 Ultra Dual-Core Mobile ZM-84
stepping	:	1
flags	:	fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow constant_tsc rep_good nonstop_tsc extd_apicid eagerfpu pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy 3dnowprefetch osvw skinit hw_pstate vmmcall lbrv svm_lock nrip_save

PCI

00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] RS780 Host Bridge
00:01.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] RS780/RS880 PCI to PCI bridge (int gfx)
00:03.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] RS780 PCI to PCI bridge (ext gfx port 1)
00:07.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] RS780/RS880 PCI to PCI bridge (PCIE port 3)
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:12.1 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0 USB OHCI1 Controller
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:13.1 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0 USB OHCI1 Controller
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller (rev 3a)
00:14.1 IDE interface: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 IDE Controller
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller
00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 PCI to PCI Bridge
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 11h Processor HyperTransport Configuration (rev 40)
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 11h Processor Address Map
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 11h Processor DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 11h Processor Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 11h Processor Link Control
01:05.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS780 [Radeon HD 3200]
02:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV516 GL [FireMV 2250]
02:00.1 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] RV516 GL [FireMV 2250] (Secondary)
03:00.0 Ethernet controller: Broadcom Limited NetLink BCM5787M Gigabit Ethernet PCI Express (rev 02)

Power Supply

The unit requires a 19V supply. The connector is a coax plug with a centre pin (see photo right). The barrel of the plug has an outside diameter of 7.4mm and an inner diameter of 5mm. I had a suitable PSU available that I used for my initial tests. It was a 60W supply that came with a t610, so my first checks of the gt7725 were done without the expansion unit fitted. (The gt7725 motherboard draws ~40W. Add in the graphics card in the expansion unit and the power drain goes up to 60W+).

The gt7725 specs mention a 120W power supply - part number NH527AA. I found that on eBay these cost over double what I paid for the gt7725 in the first place! Luckily the same connector is used on a variety of HP/Compaq laptops and so alternatives exist. As the unit with the expansion kit fitted draws ~60W+ I decided to purchase a 90W PSU to use with the gt7725. The particular listing I picked on listed a swathe of compatible HP and Compaq models, e.g. NC4400 NX6320 to name but two in the long list.

Expansion

(Click on the photo for a larger version.)

Flash: The Flash memory (top left in the photograph) is easily replaceable. It's a DOM plugged into a standard 44-pin IDE connector.

RAM: The RAM is a standard DDR2 200-pin SODIMM. There are two sockets on the board. The supplied RAM is manufactured by hynix and is marked: PC2-6400S-666-12. The part number is HYMP112S64CP6-S6. I have tried out a single anonymous 2GB part that also worked. I don't know if 4GB is the limit.

PCI-e: The board carries what looks like a PCI or PCI-e slot. This is used by the expansion module and is not a standard PCI-e connector.

There are no other headers/connectors on the motherboard.

Expansion unit The photograph on the right show the expansion unit split from the main chassis. To fit the expansion unit you remove the plastic side panel from the t7725 and remove the strip of metallised tape that normally covers the slot in the metal cover. The riser card is fitted to the expansion unit along with what ever PCIe card you want to use. The expansion unit is then offered up to the main unit with the riser card passing through the slot in the metal cover and locating in the socket on the motherboard. There are four captive bolts that pass through the expansion unit that are then tightened up to secure it to the main chassis.