Replacement PSU for Optiplex 790

hobo8086

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Dec 7, 2011
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I want to upgrade the PSU so I can use a better graphics card on the Optiplex 790. What is the best replacement with no rewiring?
 
Do you have the desktop version or the minitower version or the small form factor version or the ultra small form factor version of the Dell OptiPlex 790?

The power supply form factors are different depending on what chassis style you have.
 
Your biggest limitation is Dell's decision to limit the PCI-e x16 slot's maximum power draw to 35 watts.

That is why they only offered the Radeon HD 6450 and Radeon HD 6350 as their only discrete graphics card options. The Radeon HD 6450 is a 27 Watt card and the Radeon HD 6350 is a 19.9 Watt card.

The Radeon HD 5670 is a 64 Watt card.

The Radeon HD 6570 is a 60 Watt card.

Both of the cards, that you are considering, draw all of their power through the PCI-e x16 slot. Both cards exceed the PCI-e x16 slot's maximum power draw of 35 watts.

If you were to upgrade the power supply and use either the Radeon HD 5670 or the Radeon HD 6570 graphics card you would risk burning out the copper traces on the system board essentially rendering your system useless. The current draw through the copper traces will be greater than what it was designed to handle.

Do you still want to risk the destruction of your motherboard by upgrading?

You're better off saving up your money and buying a system that doesn't use a proprietary motherboard with such design limitations forced upon you.
 

lysinger

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Nov 26, 2010
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Would a PCIe card with external power connectors prevent his system board from burning up?
 

It may, but the graphics card manufacturers never reveal how they designed the power draw distribution between the PCI-E x16 slot and the PCI-Express supplementary power connector.

If the graphics card's power VRM circuit is properly designed it should draw its maximum from the PCI-E supplementary power connector(s) first before drawing from the PCI-E x16 slot. Well that's the way I would design it. The PCI-E slot power source should be treated as the power source of last resort by the graphics card.
 

hobo8086

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Dec 7, 2011
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What do you recommend for a system. I'm a light gamer....Golf, Madden, Lego Racers etc. Current computer is a Dell Dimension 4600 P4, but I looking to upgrade?
 
Are you looking at buying a consumer desktop or a build-it-yourself system?

Provide the following information:

Approximate Purchase Date: (e.g.: this week (the closer the better))

Budget Range: (e.g.: 600-800 USD) Before / After Rebates

System Usage from Most to Least Important: (e.g.: Folding@Home, gaming, surfing the internet, watching movies)

Parts Not Required: (e.g.: keyboard (indicate if USB, PS/2, BlueTooth, etc.), mouse (indicate if USB, PS/2, BlueTooth, etc.), monitor (list all available video input ports), speakers, OS Version (indicate whether it's the 32-bit or 64-bit edition)) **Include Power Supply Make & Model If Re-using**

Preferred Website(s) for Parts: (e.g.: newegg.com, ncix.com, etc. -- to guide in selection & pricing)

Country: (e.g.: India) we need to know where these parts are being assembled (i.e. component selection may be limited, input voltages are different)

Parts Preferences, if any: by brand or type (e.g.: I would like to use an AMD CPU & Biostar mobo with a 24" LCD and full tower case)

Overclocking: Yes / No / Maybe

SLI or Crossfire: Yes / No / Maybe

Monitor Resolution: (e.g.: 1024x768, 1280x1024, 1440x900, 1600x1200, 1680x1050, 1920x1080, 1920x1200)

Additional Comments: (e.g.: Need to have a window and lots of bling, I would like a quiet PC)
 

hobo8086

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Dec 7, 2011
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Consumer Desktop Preferred


Purchase date now

Budget $700 to $800

Photo scrapbook, gaming, internet, Microsoft Office stuff

Need all parts except monitor - 64 bit Windows 7, XP mode enabled

No preference for website

No preference for country>>>just want a stable, reliable system

Radeon HD 6770, Intel i5-2400 3.1 GHz

8gb Memory

500 GB to 1 tb drive

CD/DVD/ROM/RW+ (2) OR DUAL

Overclocking no

SLI / Crossfire no

No monitor





 
I don't recommend consumer desktops because the options are too limited. They are too proprietary and limited in upgradability as you have found.

Try the following site if you live in the US:

http://www.cyberpowerpc.com/

A lot more customization options available.
 

voxata

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Jun 26, 2012
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You most definitely can, however you WILL need to upgrade the power supply. Choose one that is the same measurements as the stock power supply - I chose a Silverstone 600w Strider. I then had to drill out the HDD cage to remove it so my graphics card could fit and tossed in an ATI 6950 2GB videocard. This is a highend card for this system for sure - runs games like a dream now.

I have the i3-2100 version with 4GB Ram. Obtained this unit used for 150 dollars.
 

swymer

Honorable
Jan 19, 2013
1
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10,510
ASUS M5A97 LE R2.0 AM3+ Motherboard - Qty: 1
Motherboard Specifications
Processor Socket AMD
Processor Interface Socket AM3+
Form Factor ATX
Processors Supported Sempron
Athlon II
Phenom II
AMD FX
Chipset
Northbridge AMD 970
Southbridge SB950
Memory
Memory Supported DDR3 1866 MHz
DDR3 1600 MHz
DDR3 1333 MHz
DDR3 1066 MHz
DDR3 2133 MHz (O.C.)
Memory Type DDR3
Maximum Memory Supported 32GB
Number of Slots 4
Audio
Channels 8 Channels
Audio Chipset Realtek ALC887
LAN
LAN Type 10/100/1000 Mbps Gigabit
I/O Ports
PS/2 Keyboard Connectors 1
PS/2 Mouse Connectors 1
USB Ports (Total) 8
USB 3.0 Ports 2
LAN Ports 1
Audio Out Jacks 3
ATX Power Connectors 1 24-pin EATX Power Connector
1 4-pin ATX 12V Power Connector
Fan Connectors 3 x Chassis
1 x CPU
S/PDIF Connectors 1
Expansion Slots
PCI Slots 2
PCI Express X1 Slots 2
PCI Express X16 Slots 2
RAID
RAID Support Yes
RAID Modes 0
1
10
5
Dimensions
Length 12 inch
Width 9 inch
AMD FX-4130 3.8GHz Quad Core AM3+ Unlocked CPU - Qty: 1
Processor Specifications
Manufacturer AMD
CPU Type Desktop
Processor Interface Socket AM3+
Processor Class FX
Processor Speed 3.80GHz
Cores Quad
L2 Cache 4MB
L3 Cache 4MB
Fan Included
Wattage 125W
Additional Technologies HyperTransport
AMD64 Technology
AMD Turbo Core Technology
Unlocked Multiplier Yes
Instruction Set SSE
SSE2
SSE3
SSE4a
Integrated Graphics Core No
Integrated Memory Controller Yes
Corsair CMX4GX3M1A1333C9 XMS3 4GB DDR3 RAM - Qty: 1
Memory Module Specifications
Memory Category Desktop
Desktop
Memory Type DDR3
DDR3
Memory Speed PC10666
PC10666
Memory Speed MHz 1333MHz
1333MHz
Memory Size 4096MB
4096MB
Total Memory Size 4GB
4GB
Memory Modules 1
1
Memory Channels Dual
Dual
Memory Socket DIMM
DIMM
Memory CAS Latency 9
9
Memory Timing 9-9-9-24
9-9-9-24
Pins 240
240
Voltage 1.5V
1.5V
ECC No
No
Memory Buffer Unbuffered
Unbuffered
Corsair CMX4GX3M1A1333C9 XMS3 4GB DDR3 RAM - Qty: 1
Memory Module Specifications
Memory Category Desktop
Desktop
Memory Type DDR3
DDR3
Memory Speed PC10666
PC10666
Memory Speed MHz 1333MHz
1333MHz
Memory Size 4096MB
4096MB
Total Memory Size 4GB
4GB
Memory Modules 1
1
Memory Channels Dual
Dual
Memory Socket DIMM
DIMM
Memory CAS Latency 9
9
Memory Timing 9-9-9-24
9-9-9-24
Pins 240
240
Voltage 1.5V
1.5V
ECC No
No
Memory Buffer Unbuffered
Unbuffered
XFX Radeon HD 6570 1GB GDDR3 Video Card - Qty: 1
Connections
Interface Type PCI Express 2.1
Interface Speed x16
Connector(s) 1 x HDMI
1 x D-Sub (VGA)
1 x Dual-Link DVI-I
Multiple Monitors Support Yes
Lifestyle
Chipset AMD Radeon
GPU Series Radeon HD 6000
Lifestyle Mainstream
Performance
GPU/VPU AMD Radeon HD 6570
Additional Features AMD HD3D Technology
AMD EyeSpeed Technology
AMD PowerPlay Technology
Maximum Analog Resolution 2048 x 1536
Maximum Digital Resolution 2560 x 1600
Video Card Profile Low Profile
Single-Slot
Memory
Memory Type GDDR3
Memory Interface 64-bit
Video Memory 1024MB
Core Clock 650 MHz
Memory Clock 1.0 GHz
Features
APIs DirectX 11
1080p Support Yes
Video Output Dual DVI
HDMI
VGA
Low Profile No
Cooling Type Fan
Multi-GPU Support CrossFireX
Minimum PSU Wattage Requirement 400 Watt
Specification Notes
Specification Notes [1] To provide the most accurate specifications, the specifications listed are based upon the manufacturer's exact model specification as published on the manufacturer's website, and the manufacturer's product documentation.
LG Internal 24X Multi Drive - Qty: 1
CD/DVD/Blu-Ray Drives GS
Type CD/DVD Burners
Performance
Cache Size 2 MB
Transfer Rate 22.16 Mbytes/s (16x) max
DVD Specs
DVD-R Write Speed 24X
DVD Read Speed 16X
CD Specs
CD Write Speed 48X
CD Rewrite Speed 32x
CD Read Speed 48X
Physical Specs
Color Black
Length 6.4"
Width 5.7"
Height 1.62"
Weight 1.54 lbs.
Configuration
Load Type Tray
Interface Type SATA
Enclosure Type Internal
Compatible Writable Media CD-R
CD-RW
DVD+RW
DVD-R
DVD+R DL
DVD-R DL
DVD-RW
DVD+R SL
Supported Formats CD-R
CD-ROM
CD-RW
DVD-RAM
DVD+RW
DVD-R
DVD+R DL
DVD-R DL
DVD-RW
DVD+R SL
DVD-ROM SL
DVD-ROM DL
Ultra LSP650 650-Watt Power Supply - Qty: 1
Power Supply Specifications
Form Factor ATX
Wattage 650W
SLI/Crossfire SLI Ready
Modular Cabling No
Special Features Manual 130v & 220v Switching
Energy Efficiency 80%
Fan 135 mm
Input Voltage 115 ~ 230
+3.3V 24 A
+5V 32 A
+12V 1 38 A
-12V 0.6 A
+5VSB 2 A
Dimensions 5.90" (150mm) H x 6.22" (158mm) D x 3.34" (85mm) W
Connector Specifications
Motherboard Connector 20+4 Pin
4-Pin P4 1
4-Pin/8-Pin EPS Connector 1
6-Pin PCI-Express Connector 2
4-Pin Floppy Connector 1
4-Pin Peripheral Connector 5
SATA Power Connector 4
Thermaltake Commander MS-I Tower Case - Qty: 1
Computer Case Specifications
Form Factor ATX Mid-Tower
Compatible Motherboards ATX
Bezel Type Plastic
Side Panel Type Window
Power Supply Not Included
Material SECC
Expansion
External 5.25" Drive Bays 3
External 3.5" Drive Bays 1
Internal 3.5" Drive Bays 5
Expansion Slots 7
Media Ports
Front USB Ports 2
Front Audio Ports 1
Cooling System
120mm Fan Ports 4
120mm Fans Included 1
Other Fans Included 1x 120mm Blue LED Fan
Dimensions
Depth 16.8"
Width 8.0"
Height 19.1"

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All for under 500.00