Studio XPS 435t / 9000 compatible processor list - General Hardware - Desktop - Dell Community

Studio XPS 435t / 9000 compatible processor list


Desktop computer Forums (Audio, General Hardware, Video)

Studio XPS 435t / 9000 compatible processor list

This question has been answered by Techgee

I am looking into upgrading a few things on my Studio XPS 435t / 9000.  Exactly what processors are compatible with my motherboard?

Verified Answer
  • Hi MathieuJSM,

    We do not suggest upgrading the processor on the system, however I have mentioned the processors compatible with Dell Studio XPS 435t / 9000:

    Intel Core i7 920
    Intel Core i7 940
    Intel Core i7 965

    Also, ensure that you update the BIOS before upgrading the processor. Click the link mentioned below for the BIOS:

    NOTE: Ensure that the system does not turn off during BIOS update.

    For more upgrades, click the link mentioned below:

    Thanks & Regards
    Manshu S

  • 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. 

    First some fine print regarding Turbo Boost and SpeedStep.  Although Dell added support for Gulftown processors (and by extension Westmere-EP Xeons) in the A15 BIOS (Note "Update BIOS to support new intel CPU (Gulftown) launch" under "Fixes & Enhancements" section), it appears they never fully tested it and/or provided a followup BIOS update to fix issues with Turbo and SpeedStep.  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.  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).  It works for a fresh boot/reboot session, but not after the processor resumes from Sleep.  After Sleep speed is stuck at base speed, providing no energy savings.

    Below is from a W3690 (Westmere-EP Xeon branded i7-990X, more or less) after a reboot.  Note base clock is 3.46 GHz (x26).  Some cores are idling (x12), but no cores ever Turbo, neither at x27 (3.6 GHz), nor x28 (3.73 GHz).  (Screen capture is of HWiNFO64 showing dynamic CPU core speeds.)

    After resuming from Sleep, all cores are stuck at base 3.46 GHz (x26) speed, regardless of CPU load.  Again, no cores Turbo.

    What this means is a 4-core Gulftown/Westmere-EP CPU at 3.46 GHz will have about the same performance as a 4-core Bloomfield CPU at 3.33 GHz, since it can Turbo to 3.46 GHz when all cores are under load.  Keep this in mind if selecting a quad core upgrade.  Since the only hex core processors available for the 435T are Gulftown/Westmere-EP it means there are no 6 core CPU options with working Turbo Boost.

    I've personally noticed Turbo not working with an i7-980 and W3690, but you can check this yourself by scanning user benchmarks for 435T on UserBenchmark.  If you drill down to the CPU for a 435T using a Gulftown/Westmere-EP processor (here's an i7-970) you'll see the average Turbo is always the same as the base CPU clock (3.2 GHz for both for the i7-970).  This isn't the case for Bloomfield processors, nor for example with Dell's follow-up machine, the Studio XPS 9100, where Gulftown/Westmere-EP CPUs can be seen if you drill down here to have an average Turbo higher than base clock, as they should.

    With that out of the way, 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 in red, one tier down in blue and what I consider a good value in green.  Only the least expensive CPU at a performance point in each tier is highlighted.

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

    Bloomfield, i7-9xx series

    Bloomfield, Xeon W35xx series

    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

    Unconfirmed quad cores

    I have no confirmation that the Gainestown Xeon W55xx series works with the 435T.  However, it uses the same LGA 1366 socket and came out about the same time as Bloomfield.  There's a report of a X5570 Gainestown Engineering Sample working in a 435MT (Mini Tower - different machine from 435T/9000, but released about same time) here.  It worked fine until a BIOS update caused it to fail to boot (likely because it was an early prototype), although it still Posted (meaning BIOS still recognized it).  The X5570 at 2.93 GHz is one step down from the W5580 and W5590 below.  Dell's follow-up machine to the 435T, the Dell Studio XPS 9100, also has confirmation of someone running a Gainestown X5550 (2.66 GHz) on Geekbench 2 here.  I'd go with the W35xx Bloomfield series instead, but if unavailable the W55xx series might be worth a try.

    Gainestown, Xeon W55xx series, quad core - may or may not work with 435T, Turbo likely works

    • W5590, 3.33 GHz - $30
    • W5580, 3.2 GHz - $25

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

    Gulftown, i7-9xx series

    Gulftown, Xeon W36xx series

    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.

All Replies
  • Hi MathieuJSM,

    We do not suggest upgrading the processor on the system, however I have mentioned the processors compatible with Dell Studio XPS 435t / 9000:

    Intel Core i7 920
    Intel Core i7 940
    Intel Core i7 965

    Also, ensure that you update the BIOS before upgrading the processor. Click the link mentioned below for the BIOS:

    NOTE: Ensure that the system does not turn off during BIOS update.

    For more upgrades, click the link mentioned below:

    Thanks & Regards
    Manshu S

  • Hi, I also own a XPS 435/9000 i bought back in 2010, it came with a i7 920 And 12 gb ram

    as of now I've replaced the video card it came with with a GTX 770 and the 450 watt psu with a corsair 600 watt. 

    I cant buy a new computer right now so I wanted to upgrade the CPU without having to change the mobo. 

    While I know this machine is quite limited for upgrading, the CPU speed is holding me back a bit, the gtx 770 is one of the fastest videocards around and while the CPU is still great, I really want to be over 3.0 ghz and overclocking with dell is not an option. 

    instead of creating a new thread I searched and found this one which is similar to my issue so I will just ask my two questions here.

    my first question is, why does dell recomend not to upgrade the CPU on the machine? What's the problem?

    and second, is the list provided in the post above still the same today? That post was on April 2013 and while the bios is still the same version as it was then, I don't know if maybe someone figured out to upgrade to a higher i7 class.

    i hope someone can help me with this.

    full specs of my machine are.

    xps 435/9000 

    i7 920 2.6ghz

    12gb of ram

    originally radeon hd 5800 now upgraded to nvidia gtx 770

    originally 450 watt psu now upgraded to a corsair 600 watt

    1tb hd (2 500 drives)

    windows 8.1

    the only other hardware I've installed myself is a PCI wifi adapter.

  • bump ?    Sad

  • Bumpity bump?

  • Is there a reason that you don't just use the 965?  It meets the specs you are looking for, and was listed by a Dell employee as being compatible (which probably is simply a list of processors with which the PC shipped from Dell as optional components).

    In theory, any of the following "could" work (Compatible Products):

    The list above hasn't changed since his post either, so nothing should have changed, but some of the above may be limited by power, cache, or speed limitations of the BIOS or system in general.  However, if the 965 works, the 975 should too, as it has the same power requirements and cache.  If the system will handle the 12MB cache of the Gulftown processors, then the 980X and 990X should also work.  Basically, if you want safe and "guaranteed" to work, then go with the 965, as recommended by the guy from Dell.  If you want a better processor, with a possibility that it won't work, then try the 9x0X.

  • Thanks for the reply :)

    I've read other compatibility lists that show that some of the higher tier 9xx don't work. Probably a cache issue as you say. Yet other posts show that they all work. I was kind of waiting for a reconfirmation from a dell employee as to why some will work, some won't and especially why they recommend not changing the CPU at all. So then I feel a bit safer before buying.

  • "I was kind of waiting for a reconfirmation from a dell employee as to why some will work, some won't"

    Well, you probably won't get it, and even if you do, it is very likely they will ONLY be able to tell you one thing:  which processors Dell validated for use in the 435, meaning only the processors Dell ever sold the 435 with as configurable options during purchase.  They most likely did not test or validate ANY other processor in the 435, since they never intended to use it.  Dell is not in the business of making white-box systems that are 100% upgradeable and customizable, so some parts are not upgrade-friendly, like control panels, chassis layout, and power supplies ... other upgrades are not "supported" simply because Dell never designed the system for that purpose.  They sell end-user solutions - computers configured to the end-users' needs.  True, their configuration options do not always meet every users' every demand, but pretty close.  That isn't to say that upgrading Dell computers "can't" be done - after all, they use standard computer parts found in other OEM systems and even sold individually at retail - Dell just can't say it is "supported" or "recommended", because they haven't tested/validated it.  It is like food that has allergy notices on it ... most foods are 99.999% likely NOT to contain those allergens, but because the company can't (or won't) guarantee that ALL allergens are absent, they put the warning on the label.  Anyone working for Dell, as a representative of Dell, can't "recommend" an unofficial solution or procedure - they CAN recommend a Dell-tested and validated solution/procedure.  He should/could, however, state that that is the reason why he must make that statement - "it may or may not work, but Dell hasn't validated any other processor" ... and language may be as much to blame there as anything.

    Whatever you choose to try, post the results here, so others may benefit from the experience.  Like so many "unsupported" upgrades and scenarios, you never know until you try ... you have only educated guesses.


  • unfortunately you are right, these machines are not great as far as upgrading.. such a big beautiful case but a locked mobo, we can't even overclock, oh well.

    I am sure the cpus he lists as compatible are the cpus that originally came with the machine, what worries me is that even those he recommends not upgrading to, which confuses me. At the very least I would like to know the reason for that recommendation, I hope it simply isn't company policy to get users to decide and buy a new machine instead!

    I found a pretty good deal for a uses i7 965, in great condition but all he sells me is the chip, no fans or heatsink etc. I wonder if I would have any problem using the fan that already came with my 920.

  • the 435t/9000, uses an X58 board/chipset, and you are talking about the Bloomfield processors, all have the same archetecture/lithography(ie 45nm,max tdp 130W ect.) from i7920 to i7975 extreme(the extreme has 6.4 GT/s QPI, but should still work) I7980 and above are 6 core processors(i believe) - I would not recommend with your locked bios....also the I7965/I975X  come with a bigger than stock fan than on the I7920, the stock fan in the 435t/9000 *** can get a I975 extreme fan ebay for 38.00(w/blue led) and bolt that to any of the bloomfield processors.As far as your confusion from Dell, its exactly what you think it is......they want you to buy a new computer, they also have not tested, etc. (by the way to change out processor fan requires pulling the board and pushing out the threaded fan mounts dell puts on there boards-they push out easy....have you downloaded realtemp to monitor heat on your I7920, i bet its runnin 60-70 celcius in that big red box............idle temps

  • Upgraded my 435T/9000 to a i7-980 (6 cores @ 3.33Ghz) when they first came out. Came with a nice heatsink/fan from Intel which seems to keep temps low.  Been running with it since, no issues. 

    If I still had the original i7-920 and was looking to upgrade today, unless I could find a good deal on a CPU, I'd probably go for a new system that is overclockable - 435T has no such options in the BIOS. 


    The "official" support for the Intel Gulftown processors was buried cryptically in a BIOS update note which I can no longer find on Dell's website.  A15 BIOS firmware update stated (from my 2012 screen capture below):

    "Update BIOS to support new intel CPU (Gulftown) launch."

    The Gulftown processors included i7-970, i7-980, i7-980X and i7-990X (wikipedia).

    From my notes I kept dated November, 2011, I was able to find users on the Dell Commmunity site with the 435T running i7-970 and i7-975.

    At the time, I inferred that since the older i7-975 worked for another user, up to the Gulftown i7-980[X] should also work, since they have the same 25x Multiplier. 

    But, note while the I/O bus speed on i7-920 and i7-980 are the same (4.8 GT/s QPI),
    the i7-980X and i7-990X CPUs support speeds of 6.4  (although they may step down to 4.8 - not sure).  This may or may not be an issue with i7-980X / i7-990X compatibility.  I personally have never seen users stating they're running a Dell Studio XPS 435T 9000 with either a i7-980X or i7-990X.

    Below is a screen capture from Dell's site I took on January 9, 2012 - note the "Features and Enhancements" section:

    EDIT:  Although A15 is no longer listed under 435T/9000 Support, the link in the above screen capture still seems to work:

  • HWiNFO details of 435T/9000 with 6-core i7-980.  Note what 435T/9000 is capable of:  48GB memory (requires Windows Vista/7 Pro/Ultimate or Windows 10 (any version) to get past Windows 8/16GB memory limits).  Also running 3 SSDs and 2 optical drives and a Sapphire HD 7850.  (This system has also been upgraded to support USB 3 with an add-in PCIe card.)  Original motherboard and PSU (although it's near its limits).

  • Techgee, how are you running ssd's at 6gbs,- from memory I thought that was 2nd gen sata (3gbs) i still have an old 435t in a closet somewhere...maybe I should dig it out..

  • Techgee this (gulftown support) should be in the following A16 bios correct?....I think I upgraded from A12 to A16

  • You're correct - SSDs are capable of running at 6Gb/s, but are not running at that speed, since 435T/9000 only supports 3Gb/s.

    If I drill down to each SSDs in HWiNFO it shows it more clearly:

    Serial ATA 6Gb/s @ 3Gb/s

    I personally find 3Gb/s fine, as in most cases I'm limited by Gigabit Ethernet speeds or 4K read/writes (I don't know of any SSD that can do 4K faster than 3Gb/s).

    You can see I'm running the last BIOS, A16, in the lower left hand section of HWiNFO.  i7-980 Gulftown reported at top left.

    Hope that answers your questions.

  • I mothballed my 435t/9000 (in a closet somewhere) in 2014 and built 2 new systems, but am thinking about pulling the 435t out for my youngest child as a beginner rig,

    upgrades:  i7 975x, 24 gb gkill ram, corsair cx 750, amd 7870 gpu, samsung 128 gb ssd, asetek 545 liquid cooler(92mm fans), 2 combo optical drives, 2 wd blacks 2tb, also tp link 4800 wireless card, the old dell was running good when I mothballed her.. 

    your posts on this old thread is what got me thinking about it....thanks... I think