Question Dell XPS 420 Upgrades

Jan 2, 2020
Looking to upgrade some parts on my Dell XPS 420 Desktop


Model Dell OTP406
Socket Socket 775 LGA
North Bridge Intel X38 rev 00
South Bridge Intel 82801IR (ICH9R) rev 02
BIOS Dell Inc. A07 (02/25/2009
FSB 1333/1066/800 MHz

CPU Name Intel® Core™2 Quad CPU Q6600 @ 2.40GH

I am looking to upgrade four (maybe five) components.

1. CURRENT PSU - Stock PSU 450 W


If this PSU is not sufficient, please give another suggestion.

2. CURRENT HDs Storage (HDD/SSD)
(Ignore RAID, it is corrupt/broken)
Model #1 Name SAMSUNG HD321KJ (FW: CP100-13)
Model #1 Capacity 298.1 GiB (~320 GB)
Model #1 Type Fixed - Bus: RAID (8)
Model #2 Capacity 298.1 GiB (~320 GB)
Model #2 Type Fixed - Bus: RAID (8)


Total Size 4096 MB
Type Dual Channel (128 bit) DDR2-SDRAM
Frequency 332.5 MHz (DDR2-666) - Ratio 4:5
Timings 5-5-5-15-2 (tCAS-tRC-tRP-tRAS-tCR)
Slot #1/3 Module AENEON 1024 MB (DDR2-662) - P/N: AET760UD00-30DB97X
Slot #2/4 Module Qimonda 1024 MB (DDR2-662) - P/N: 64T128020HU3S

Looking for fastest MoBo/CPU compatible RAM 8 GB (4 X2GB)

GPU Type ATI Radeon HD 2600 XT (RV630) @ 800 MHz
GPU Brand Dell
GPU VRAM 256 MB @ 1100 MH

Radeon 5800 Series?

EVGA GeForce GTX 750Ti Superclocked 2GB GDDR5 Graphics Card 02G-P4-3753-KR?

1024MB GeForce 9800 GT?




Really would like to keep costs in the $250 USD range.

Micro center is 1/2 hour away.
First and foremost, I'd upgrade to a q9xxx series processor since you can. You can also try using throttle stop to overclock the q6600, but the q9xxx series is a drop in replacement at stock voltages/speeds.

Next, I wouldn't replace the Dell power supply with Best Buy house-brand junk. The Dell power supplies are made better than the BB ones by a long shot.

Storage--do whatever you wish really--ssds are cheap and work well. One large drive or 2x in raid0/1 for bulk storage.

Ram--Any 800mhz ddr2 2b modules will work. If you want something 'faster' I would get some ram with closer timings.

GPU--as much as the power supply can handle and bios will allow. The 750Ti is always a favorite since it doesn't need a power plug, but you can even get a 1660 in there.

HSF--you can't change this as it's a BTX style cooler and proprietary Dell. However, stock is a really nice heatpipe cooler, so it should do quite well. You can always use better paste to max it out.
Jan 2, 2020
Q9650 looks nice compared to Q6600; but, I don’t know if it’s truly worth the risk to buy refurbished CPU given price is anywhere between $90 & $150. I have intent to hold off on making a completely new build ( 1-2 years for now since I am making certain upgrades to XPS 420 right now.

CPU: Are there any Q9xxx processors on the market that are still new but super cheap?
Is this truly brand new?

PSU: Ended up getting EVGA.
It took some effort to align screw holes but we managed.

SSD: Bought this one on sale.

I want to make this one my primary OS drive but am unsure if the SSD should be setup as MBR or GUID. How do I determine which given my MoBo listed above? I don’t see any option to choose between BIOS/UEFI in the BIOS settings. My BIOS version is A07 (02/25/09).

Just double-checked current RAM has speed of DDR2 667 MHz.
OPTION 1: Price for DDR2 800 MHz 8GB $45 (Well known brand)

OPTION 2: Price for DDR2 800 MHz 8GB $34 (Not well known brand)

GPU - I am probably going to hold off on GPU for now; but I’m not against additional information, and with enough info I might even be convinced to spend a bit more for the upgrade. My PSU is 600W. If I was to get 750 Ti, it requires 400W PSU, for example. How do I determine “How much GPU” my BIOS/MoBo (Dell OTP406) will allow?

HSF - Okay, can’t upgrade. I am using thermal paste below:

Given the upgrades I’ve already made to the system, I’m somewhere in the neighborhood of $165 spent. I would like to spend on this system a max of $300, so that leaves about $140 to work with for RAM upgrade (Definitely), CPU upgrade (Risk Vs. Payoff?), & maybe a GPU. I am still very much in the dark & definitely need more information to make informed decision and then possibly I can increase my spending limit from $300 to $500, in order to make final decision on CPU upgrade to Q9650 and even accomodate a new GPU.
Well, if you take one step back, and get a Q9550 insetad of a Q9650, the prices for used CPUs suddenly drops dramatically.

Honestly, the money is NOT well-spent in upgrading the existing system. A low-end system on a modern platform can be put together fairly easily for that $500 limit, and get you MUCH farther than upgrading the existing system.

Now, this doesn't count the cost of the OS, but the following is more capable than your existing system.

PCPartPicker Part List

CPU: AMD Athlon 3000G 3.5 GHz Dual-Core Processor ($49.00 @ B&H)
Memory: G.Skill Ripjaws Series 8 GB (2 x 4 GB) DDR4-2400 CL16 Memory ($31.99 @ Newegg)
Storage: Patriot Scorch 512 GB M.2-2280 NVME Solid State Drive ($96.31 @ Amazon)
Custom: ASRock DESKMINI A300W AMD Socket AM4 1 x HDMI Barebone System ($157.98 @ Newegg)
Total: $335.28
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2020-07-29 17:58 EDT-0400

The CPU can be bumped up to the 3200G for $50 more. It will perform better than your existing system, or the 3000G would be about equal to, maybe slightly more capable than, the Q9650, while consuming far less power.

  • That particular EVGA PSU is a low quality unit. Return it.
  • The WD SSD you got should be usable in the ASRock DeskMini unit - so you can use that in place of the Patriot I put in.
EDIT 2: note that this machine can ONLY use CPUs with integrated graphics. Also, it uses laptop RAM.
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Actually the risk is on getting any 'new' lga775 processor as they are most definitely fakes.

A good used processor is completely fine. I have over a dozen used lga775 (and other gens too) running well for years now.

Like I said, I wouldn't have upgraded the power supply. I have an optiplex 330 that has a swapped in 380 motherboard, a x3360 (q9550 xeon twin), 4gb of OCZ PC2-6400 ReaperX ram, a 250gb hard drive, and a evga gt 9500 which should be right at the limit for the 280w stock Dell power supply, but it's been working fine for years in a room that's 80F (and is almost 100F right now). Your system comes with a much beefier power supply so it's good to go as it is. I would return the evga and use the money elsewhere.

As far as what to do with the SSD--just boot up a live version of clonezilla and clone your existing drive to the ssd, remove your hard drive and boot on the ssd. After a few weeks once all is well, you can re-purpose the hard drive as additional storage or keep it as a backup.

I wouldn't buy any new ram--just used. And I wouldn't try to get anything fancy--any DDR2-800 will do. This should be under $30 shipped for a whole lot of 4x2GB for a total of 8GB, most of this being the cost of the shipping.

Because this is an older system, you can easily have 'too much gpu'. If you look at the EVGA 750Ti SC, it is a low powered card that doesn't require any power connector and should work fine with your stock Dell power supply. It's also cheap at around $40-45 used.

The real limitation on gpu will be if the gpu requires a uefi bios. This is typically the case for newer top-of-the line cards, but for something that will work with what you have (low profile or power-less), you won't have to worry about that. This means even a low profile 1030 or 1050 or 1650 would probably work, but these are more expensive cards.

When upgrading, you have to be careful about spending 'more than it's worth'. Ie, you can get a newer much more powerful system for the same or even less money.

Perfect example is this older i5-3470 Dell at pcliquidations:

For just over $100, you will have a machine that will simply blow away a q9650, even when maxed out:

And if you allow the budget to creep higher, you get even more performance from newer components--it is all about how much you want to spend and how much work you want it to be. One of the drawbacks of newer systems that no one really talks about is the configuration and setup time. It's pretty easy to upgrade to 8GB of ram and simply get back to work in 15 minutes. Upgrading to a newer computer can take days to get configured. And that time is an opportunity cost.
I'm building one of those right now.
QX9650 @ 4.32Ghz,12GB DDR2 800,GTX1060 6GB Dell 425W PSU from a T3400 workstation.
The 4GB DDR2 800 low density (512x64) modules are very expensive. But 8GB DDR2 800 is easy. Must be 256x64 modules.
The QX9650 and T9303 heatsink will get you 4GHz. with Throttlestop software. It also responds to SetFSB.
If you have a Dell 450W PSU keep it.
For an 8GB RAM machine either a GTX1050Ti4GB, or a GTX1060 3GB GPU will be nice. I prefer the 1060 3GB.
There aren't any good builds of that yet at userbenchmark, so I will give a link to the Precision T3400 workstation which is the same thing with an extra GPU slot. Anything scoring in the 60% range will be an overclock.
Post #946,947 here show my build. But the custom BTX big air cooler is a work in progress. Fabrication skills required.
Here's a T3400@ 4.15Ghz. I know the guy who did that. No special tricks involved.
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TJ258 is a nice cooler upgrade. You just have to saw a platic brow off the top and fill/cover the hole.
For cheap thrills you could play around with a QX6850 overclock. they're unloved and the good G0 stepping.
Shop by the SLAFN code and you might get a better deal.
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