What is difference between studio xps 8000 and 8100

What is difference between studio xps 9000 and xps 9100?

both are formerly called xps 435T

9000: 475 w psu

9100: 525 w psu

both have x58 chipset support i7 1st gen cpu and Xeon equivalent including 6 core gulftown

good read to archive

Dell Studio XPS 435T/9000

Since there doesn't seem to be a good consolidated list of possible CPU upgrades for the Dell Studio XPS 435T/9000, thought I'd put one together here.  Although I've listed below the Intel series that have shown to work, I only focus on the top CPUs in each series since that's likely what you'll want to upgrade to.  Also, for reference I've listed approximate prices on ebay, to give you an idea of cost.  Prices can vary widely depending on where and from whom you buy from.  Ebay seems to be cheapest, but caveat emptor on Sellers.

Determining what CPUs work can be based on several things:  1) Dell's BIOS update description listing adding CPU series support, 2) my and others experience on web trying different CPUs, 3) user benchmark sites and 4) description of sales of used 435T machines.  Generally, if the fastest CPU in a series works, the entire series is assumed to work.

Intel Xeon processors that work for the 435T are cheap (often half the price of corresponding retail/consumer i7 processors) because businesses are replacing their systems and their older Xeon processors are being sold in the secondary market.  Note Intel Xeon branded CPUs generally contain extra features for business users that retail/consumer CPUs do not.  Since their base feature set is usually the same, a Xeon processor can often replace its corresponding retail/consumer processor (but usually not the other way around).  The extra features just aren't used in the 435T. 

Note there is no Turbo Boost for any of the Gulftown and Westmere-EP series when running in the 435T - max processor speed is the base speed.  Basically, this is all hex cores and the X56xx series.  On average this results in a performance loss of about 0.133 GHz.  Also, there's an issue with SpeedStep (idling at a lower-power processor speed under low/no load) not working after Sleep.  There is a partial workaround for the Turbo and SpeedStep issues.  For details, see this post.

Here's the list.  For reference, many 435T's came with an i7-920, a quad core which runs at 2.66 GHz.  Note where I could find user benchmarks for a specific CPU I've linked to them.  For both 4 and 6 cores, I've highlighted top CPUs that are also a good value in green.  Processors with Unlocked Multiplier next to them can be overclocked with software (I'll post a link later).

 
Top quad core CPUs that work or should work in 435T/9000

Bloomfield, i7-9xx series

• i7-975, 3.33 GHz, Unlocked Multiplier - $80 - *UserBenchmark (10 hits), Geekbench 2 (6 results), Geekbench 4 (2 results)
• i7-965, 3.2 GHz, Unlocked Multiplier - $65 - *UserBenchmark (1 hit), Geekbench 2 (1 result)
• i7-960, 3.2 GHz - $55 - *UserBenchmark (25 hits), Geekbench 2 (15 results), Geekbench 3 (13 results), Geekbench 4 (3 results)

Bloomfield, Xeon W35xx series

• W3580, 3.33 GHz, Unlocked Multiplier - $30 - author (details here), Geekbench 4 (1 result)
• W3570, 3.2 GHz, Unlocked Multiplier - $20
• W3565, 3.2 GHz - $10 - author (details here), Geekbench 3 (1 result)

Westmere-EP, Xeon X56xx series, no Turbo with 435T

• X5687, 3.6 GHz - $50 - *UserBenchmark (2 hits)
• X5677, 3.46 GHz - $35
• X5672, 3.2 GHz - $30

Gainestown, Xeon W55xx series - may or may not work with 435T

Likely works, but W35xx Bloomfields are a better choice regardless.  See post here for details.

 
Top 6-core CPUs that work or should work in 435T/9000
no Turbo with 435T

Gulftown, i7-9xx series

• i7-990X, 3.46 GHz, Unlocked Multiplier - $250 - *UserBenchmark (2 hits), Geekbench 3 (1 result)
• i7-980X, 3.33 GHz, Unlocked Multiplier - $165 - *UserBenchmark (11 hits), Geekbench 2 (6 results), Geekbench 3 (10 results)
• i7-980, 3.33 GHz - $125 - author (details here)
• i7-970, 3.2 GHz - $110 - *UserBenchmark (5 hits), Geekbench 2 (2 results)

Gulftown, Xeon W36xx series

• W3690, 3.46 GHz, Unlocked Multiplier - $115 - author (details here), Geekbench 4 (1 result)
• W3680, 3.33 GHz, Unlocked Multiplier - $80 - Geekbench 3 (1 result), Geekbench 4 (1 result)
• W3670, 3.2 GHz - $55 - Geekbench 4 (3 results)

Westmere-EP, Xeon X56xx series

• X5690, 3.46 GHz - $120
• X5680, 3.33 GHz - $80
• X5679, 3.2 GHz - $90
• X5675, 3.07 GHz - $45
• X5670, 2.93 GHz - $40 - *UserBenchmark (1 hit)
• X5660, 2.8 GHz - $25
• X5650, 2.66 GHz - $25 - *UserBenchmark (2 hits), Geekbench 3 (1 result) , Geekbench 4 (3 results)

 
*UserBenchmark results for Dell Studio XPS 435T/9000 - if CPU not listed under "CPU" tab here or here (clipped to top 11 results), then scan all User Benchmarks for the specific CPU here and here.

studio XPS 8100

https://dl.dell.com/manuals/all-products/esuprt_desktop/esuprt_studio_xps_desktop/studio-xps-8100_user's%20guide_en-us.pdf

studio XPS 8000

https://dl.dell.com/manuals/all-products/esuprt_desktop/esuprt_studio_xps_desktop/studio-xps-8000_user's%20guide_en-us.pdf

studio XPS 7100

https://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_studio_xps_desktop/studio-xps-7100_setup%20guide_en-us.pdf