Single slot cards with 1 fan can fit. James83Alienware. Buy some contact cleaner and spray the RAM contacts as these desktops love to complain about RAM fault when RAM contacts go bad. 1 with 8GB. Officially, (according to the Dell Technical Guide Book for the Optiplex GX 755) the max CPU and RAM are: Intel Core 2 Quad Q6700 Processor (2. Memory. Sep 20, 2011. 2: M. McCandless Twp, Pittsburgh Google Pixel Watch 2. I also specified 2 GB of PC2-6400 800Mhz of DDR2 memory as part of the original configuration that was supplied by Dell. Above Optiplex's are a little less old. 755 never came with win7 / 7 drivers/ 7 COA from dell. Only one thing changes RAM speed. -. FREE delivery. 2 slot supports 4X. Optiplex 755 desktop pdf manual download. System Requirements. compare. sp. Speed was pretty good though. 89 inches centimeters Length 6. Power figures for DELL Optiplex 755 Mini Tower. J. . Patriot Signature 4GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Desktop Memory Model PSD24G8002Memory speed issue after Optiplex 755 Memory Upgrade. Optiplex 755. I want to install 64 bit Linux so I got 2 new 2GB memory sticks and replaced the 2 1GB ones, into the same slots. Maximum Memory; 16GB: Memory Expansion Slots / Banks; 4 Slots: Memory Type & Info; PC2-5300/6400 DDR2 SDRAM DIMM Intel Q35 Express Chipset. Good day Sirs, I have Mini Tower OptiPlex 755 with 0GM819 motherboard. Motherboard: Dell OptiPlex 7010. 89 $ 64 . I've read in a few places that if any of the versions of Windows are on 32-bit, they only use a max of 4GB. 7040 takes 6th gen CPU's. Memory: Ultra Small Factor model: Up to 4 GB 800 MHz / 667 MHz Non-ECC SDRAM DDR2,. The following table lists the memory specifications of your OptiPlex 5000 Small Form Factor. Your OptiPlex 755 supports these operating systems: Change Product. $50. 0. sys and make sure that this file is on the SSD with at least 1. The list spans from 1996 to 2023 and includes CPU compatibility, chipset type, number of memory slots, maximum ram and the ram speed. Buy system specific Dell OptiPlex 755 DT/MT/SFF Desktop Memory/RAM and SSD upgrades from KingstonMemoryShop. . $999. When I put Win10 on an SSD and maxed the RAM, that's when I really noticed a difference in speed. OptiPlex 170L. However, is says the minimum watt supply requirement for this GPU is 400 Watts. $14. product OptiPlex 755 version unknown serial 8TQGJ3J UUID {4C4C4544-0054-5110-8047-B8C04F4A334A} SKU unknown family unknown DMI Baseboard vendor Dell Inc. Download the PDF file and follow the instructions for installing hardware, software, and drivers. (example: DDR3L) DDR3 is not backward-compatible with DDR2. Dell Optiplex 755 Series GM819 Motherboard. I really don't know that you'll notice a difference in RAM speed between 667MHz and 800MHz simply using the PC. 731 / 6. 5: wait 15minutes, this further discharges huge capacitors inside. Genuine A-Tech Brand. +. 30-07-2011 16:00 PM. Slots: 4. Then on the screen to the right, select RAID Autodetect / ACHI. HERE is the Crucial Memory listing for the 380 "mini tower". You might need to rollback your SSD to a 256 GB model. Six years later, my replacement Optiplex 755 Desktop has failed. DDR4-2666 • CL=19 • NON-ECC • UDIMM • 288-pin • 1. 1 with 8GB. The biggest issue with Dell memory is the need for low density memory. 00 Used;OptiPlex 755 upgrade. If you plan on getting the 6770 inside th new 780, you'll most likely see same performance. Good day Sirs, I have Mini Tower OptiPlex 755 with 0GM819 motherboard . Memory connectors. Intel Core 2 duo E7500 2. #3. Effective Memory Clock: 1200MHz; Model #: EAH6450 Silent/DI/1G; Item #:. The CPU upgrade is the area I'd appreciate some advice. [New] Apple Mac Studio: M1 Max - 32 GB Memory - 512 GB SSD - Silver. $64. So I guess this should be high density. 4. Maximum Size SSD for XPS 8940. the modern intel motherboards are almost all ATX (or proprietary). The Mr Memory upgrades below are 100% Compatible for your Dell. I'm thinking of upgrading my GPU to GTX 1050 Ti Low Profile, upgrading the memory up to 16gb or 32gb and upgrade the HHD to 1TB and replace the optical drive. Dell only lists what was available and tested with that system when new. 89 I have two Optiplex 755 SFF running VMware ESX 4. I used a Q9650 in my previous 755, maxed the RAM to 8GB, used an SSD, and the thing flew. A 780 can take a Q9650 Intel Core 2 Quad 3. Dell Optiplex 7010 Small Form Desktop, Intel Quad Core i7. Your PC won't break if the wrong selection is made, it simply won't boot. Yes the machine is a good Deal IMHO. PC2-6400 would be preferable if you are using the IGP. 33GHz 4M,VT,1333FSB 330-1129 : Shipping Material for System Single Hard Drive Neo Desktop Dell OptiPlex 365-0257 : CFI Routing SKU 366-1551 : Custom Project Fee for ESLH 313-5426 : 16X DVD+/-RW,SATA,Dell OptiPlex. Optiplex SFF Plus 7010, RAM upgrade. Replaced a L305P-01 (305W) PS and upgraded the memory to 4Gb. Optiplex 5000 Small Form Factor. 25-inch drive bay 3 3. Hello, I have a Dell Optiplex 755 (DT) and I currently have 4GB of DDR2. 64. Max memory for Optiplex 780. 93 GHz, BIOS is A16 8/16/2013, installed memory is 4GB. Can someone confirm the RAM capacity of an Optiplex GX 280? I bought a used machine, it is fitted with 2 x 512 MB. Optiplex. 0 GB Windows XP Home, Intel Graphics Media Accelerator 3100 32 MB DDR 256 MB (shared). Drives > SATA Operation. Dell Latitude 9430 Maximum Memory Support. Dell Optiplex 755 SFF RAM upgrade problem. Visit the A-Tech Store. and I want to upgrade my RAM in case of use optimally FSB (MHz). . Tengo 4 memorias ram de 1gb en mi optiplex 755, quiero aumentarla a 8GB. 00GHz Yorkfield Quad Core Q9650, 12MB. DDR3 and DDR3L are socket compatible, however, It is NOT compatible with computers using 4th Generation Intel (Haswell) processors, which exclusively support 1. It is the latest version of synchronous dynamic random-access memory (SDRAM). . Get the lowest price deals on Amazon, and eBay. Aug 7, 2017. 81 $ 50. Why does crucial recommend a higher maximum ram limit for my system than the system manufacturer? At Crucial®, we ensure that the higher amount of RAM is rigorously. 1 with 8GB. Dell Optiplex 755 Full-Tower Desktop Specs and Details. Are you sure I don't need a new power supply? I got the Ram and Hard drive covered now, so i don't need to worry about that, neither the CPU. Dell Support Driver and Downloads not offering manual downloads for my XPS 8940. Hello, I'm planning to upgrade my OptiPlex 755. PC Dell optiplex 755 Slim Core 2 Duo HDD 250gb ram 4gb. the maximum supported Cpu is a q9650. Or fastest delivery Nov 7 - 8 . I have two Optiplex 755 SFF running VMware ESX 4. The latest BIOS for your 755 is A22. I have multiples of the Optiplex 755 and XPS 420's- They're great little machines for virtualization. Upvote 1 Downvote. Conectores de memória 4. The technical guidebook to the 7010 says that each of the four DIMM slots can handle up to 8GB memory modules, but then says the system maximum is only 16GB. Guaranteed Compatible with Dell Optiplex 755 Small Form Factor Computer. DDR3-1600MHz can be used & what I posted above, but. Be sure to avoid KVR (Kingston Value RAM), as this has caused problems in Dell's. Intel Core2 Quad Q9650 (Clock speed at 100%) with NVIDIA GeForce GTX 750 Ti (Clock speed at 100%) x1 will produce only 2. Crucial Memory and SSD upgrades - 100% Compatibility Guaranteed for Dell OptiPlex 755 Series (Desktop Mini-Tower and Small Form Factor) - FREE US Delivery. OptiPlex 3090 Ultra Form Factor. I have got a Dell Optiplex 755 SFF, and i'd like to change all of my hardwares, to the best components what i can use. Isso é algum problema de configu. 66GHz (2 CPUs), ~2. 0. Optiplex 5000 Micro. It's an Optiplex 755 SFF with windows 10 64bit, so I'm going with 8GB ram (2 x 4), an SSD in place of the old HDD. have a Dell Optiplex 755 MT that was purchased as a barebones w/o a processor, memory or hd. 4. This item: 8GB 4X2GB Dell OptiPlex 755 Series Desktop/PC DDR2 PC2-5300 RAM Memory. 2 device into a 2. Thats why server boards that have more memory use regsitered buffered ram and support 128 256 512 gigs etc. 0 (6Gb/s) Show full device specification. Max Dimm size for this model is LOW Density INTEL compatible Ram 2 gig modules. Desktop Computer (DT) View . Dell 755 optiplex. Dell equipped high end CPU Optiplex 755 models with 800 MHz memory, low end models with 667 MHz memory (Dell Optiplex 755 Technical Guide Book,. cannot be used by computer memory; therefore, the amount of memory availab le to the operating system is less than 4GB. By tech_guy in forum Hardware. Updating to a different Dell is also in mind. I do have a PCI-E slot in that computer and AGP. #5. com. 6. What is the max speed of ram this machine can handle? Typically I have seen machines with. 5-inch internal SSD • SATA 6. All of these can accept 8GB of DDR2 except the crippled G31 is unable to remap PCIE/APIC memory to above 4GB so can never actually use more than 3. Nov 22, 2016 Should be 16 gb max source :more info here You have to choose between 2 x 8 gb ddr2 OR ddr3 because you cannot mix them. Will have a i7 7700. 8GB maximum = Four 2GB DDR2 800MHz memory modules. I have a upgraded version of the dell inspiron 3511 where i have 8 gb of ddr4 ram, i was going to upgrade that to 16 in the near future but dont know if. DELL ™ optipLEx ™ 755 tEchnicaL guiDE book insiDE thE optipLEx 755. You'll get MUCH WORSE performance. This fault usually occurs about once per week. - RAM tests include: single/multi core bandwidth and latency. Replacing the. 25-inch drive bay 2 5. Buy some contact cleaner and spray the RAM contacts as these desktops love to complain about RAM fault when RAM contacts go bad. Dell OptiPlex 755, like many other OptiPlex in this era, uses BTX standard (Inverted ATX), so no ATX and ITX family motherboards (even Micro ATX or Mini ITX) will FIT! Max RAM is 8GB (4x2GB). Later in the boot process, it will. The memory speeds supported include 667 and 800 MHz DDR2 memory. 2. Why does crucial recommend a higher maximum ram limit for my system than the system manufacturer? At Crucial®, we ensure that the higher amount of RAM is rigorously. Optiplex 755 DDR 2 Ram question. Do all the RAM chips match in size, speed, and brand name? Couple of things to rule out there before it can be asserted if it's RAM or MB. That's why higher than 8GB is. View PDF. 0. Exact same specs as the shipped version, but the system will not accept it and will not boot. Type. Mi pregunta es ¿Puedo colocar en una de las ranuras libres una memoria ram kingston kvr8002N6 de 2 GB a 1. If you are using a 32-bit operating system such as Microsoft® Windows® Vista®, your computer will support a maximum of 4 GB of memory. Aurora R4, computer won’t boot with Intel Xeon E5 2697 v2 in LGA2011 socket. Dell & Intel (especially Intel) didn't bother with revising their specs to reflect the times, or wasn't correct from the start, as we all know that the Optiplex 780 mid-tower & DT edition can run 16GB total RAM (DDR3-1333MHz). Artemis08. Non-ECC dual-channel 2400MHz DDR4 SDRAM (2133MHz performance on. The actual. if your looking at one of these i would reccomend them because they blend into everyday use and tasks. Even the LP HD6670 is too high a card, the system requirements are stated as. Dell™ optiplex™ 755 technical guiDe systEM boarD connEctor MaxiMuM aLLowabLE DiMEnsions usff PCI Slot (s) Dimensions: (HxL) Height 4. 8GB ram ddr2 @ 800Mhz will work, as I’ve upgraded from 4gb in my 755 DT. Dell Support Driver and Downloads not offering manual downloads for my. 36-070314a3-045812E-Dell. Design 1st OptiPlex was the first Dell product made with recycled materials in 2007. - SkillBench (space shooter). OptiPlex 210L OptiPlex 210Ln OptiPlex 3000 Micro OptiPlex 3000 SFF OptiPlex 3000 Tower OptiPlex 3010 Desktop OptiPlex 3010 Mini Tower OptiPlex 3010 Small Form Factor OptiPlex 3011 All-in-One OptiPlex. 6 / 16. and I want to upgrade my RAM in case of use optimally FSB (MHz). 6 Professor. 8 Gb/s (DDR2 800. 2 GB of DDR3 GPU memory with fast bandwidth enables you to create large, complex 3D models, and a flexible single-slot and low-profile form factor makes it compatible with even the most space and power-constrained chassis. Where to buy. I have a Nvidia Geforce GT220 video card, which is a low profile video card, it can consume the maximum of 58 W, and this video card requires at least 300 W works without problems. 07-01-2013 05:00 AM. 3 out of 5 stars (3) $13. I've got a Nvidia Geforce GT220 Video card, which is a low profile video card, it can consume maximum of 58 W, and this video card requires minimum of 300 W to work properly w/o. This system rating = 2134, 2D=482, 3D=1872- quite. We have a Dell OptiPlex 755 where the diagnostic lights will often show a 3 4 pattern. 512 MB, 1 GB, or 2 GB non-ECC. This computer supports maximum memory speed of 800MHz DDR2 SDRAM. In reference to processor upgrade, Dell has only tested Optiplex 755 with the Intel Core2 Quad, Core2 Duo, Intel Pentium dual-core, Intel Celeron processors based on Intel's 775-pin (LGA775) socket. Hi cutlassvillager1, The differences are fairly minor. Memory Type & Info. Connect the display to the port on the discrete graphics card. To get the best performance and speed from your Optiplex, upgrade to the maximum memory. A-Tech 8GB (4X 2GB) Max Memory RAM Kit for Dell OptiPlex 755, 745, 740, (MT, DT, SFF) - DDR2 667MHz PC2-5300 Non-ECC DIMM Upgrade. NA / NA / NA / NA. 0. Eligible for Return, Refund or Replacement within 30 days of receipt . 5" bay : Additional information : 9350 9360: 1: 1x M. Ad. 01TKCC motherboard. 9. I have heard conflicting info that either 4gb or 8gb is the max it can handle. This system supports 8GB (2 Dimms) of DDR3. My Optiplex 755 (desktop) came with 2 1Gb 800MHz sticks and I'd like to add another 1Gb, i. What type of memory does the Dell Optiplex 755 Desktop Computer take? The Dell Optiplex 755 Desktop Computer takes the DDR2 PC2-5300 667MHz, PC2-6400 800MHz DIMM. In the next generation of Optiplex's, models like the 390, 790, 990, etc. 5 out of 5 stars 15. Memory specifications . The CPU upgrade is the area I'd appreciate some advice. Make optimal use of your installed memory. 0. For best Optiplex 755 Small Form Factor Computer performance use the maximum amount of 16GB, fill all the slots with the max allowed memory per slot for your Computer. com Search El equipo OptiPlex 755 soporta memorias DDR2 SDRAM de 667 o 800 MHz, para que el ordenador reconozca los 8 GB de memoria, es necesario que el equipo tenga instalado un sistema operativo que trabaje a 64 bits. Shop Amazon for A-Tech 8GB (4X 2GB) Max Memory RAM Kit for Dell OptiPlex 755, 745, 740, (MT, DT, SFF) - DDR2 667MHz PC2-5300 Non-ECC DIMM Upgrade and find millions of items, delivered faster than ever. Max System Memory: 8 GB: Installed Memory: 2 GB: Memory Socket: DIMM: Memory Technology: DDR2 SDRAM: System: Drive Controllers: Serial ATA: Interface Connection:Here's what I know about my pc: 223-0731 : OptiPlex 755 Desktop Energy Smart,Core 2 Duo E6550/2. Connect the power cable. Tengo una Dell Optiplex 755 que viene de fabrica con 4Gb de RAM de 667MHz, pero tengo entendido que esta solo soporta hasta 8Gb de RAM con una frecuencia de 667 MHz a 800MHz, entonces yo se la quiero mejorar a 8 Gb pero no se cual comprar ya que ya he probado con unas memorias ddr2 de 800MHz pero no arranca la. OptiPlex XE Technical Guidebook Page 2 OVERVIEW . good day! I have a DELL optiplex 755 SFF PC. Crucial Memory and SSD upgrades - 100% Compatibility Guaranteed for Dell OptiPlex 755 Series (Ultra Small Form Factor) - FREE US Delivery. Over 100 total manuals, tech guides, spec sheets, & etc. 2GB RAM (1x2GB) INTEL GMA3100 ( :C ) 150GB HDD. 2GB Kit 2 X 1GB DDR2 Memory for Dell Optiplex 330 740 745 745c 755 Desktop PC2-5300 240 pin 667MHz DIMM RAM. Best CPU for it is C2Q Q9650 3. bradthetechnut. Checking Passmark Performance Test baselines, the highest rated system uses a Core2 Quad Q9650 - 4-cores and 3. These have Dell extra features like ambient temperature sensors, and 4 led diagnostic displays. 30,340. Then we started Windows, only 256MBs of Ram out of the 8GBs was available (the OS told us). 89. Why does crucial recommend a higher maximum ram limit for my system than the system manufacturer? At Crucial®, we ensure that the higher amount of RAM is rigorously. ovErviEw 3 Mini Tower Computer (MT) View 5. 0Gb/s • 540 MB/s Read, 500 MB/s Write. OptiPlex. 0 5 Dell™ optiplex™ 755 technical guiDe 5 front view 1 5. 2. Rp325. $64. Starting at CAD $599. A empresa acaba de adquirir dois Optiplex 755 Core 2 Quad com 4 Giga de Ram e HD 150 Giga Raid 1, porém esta sendo disponibilizada para utilização do SO 3 Gigas. 0 (6Gb/s) Show full device specification. Core, Intel Inside, Intel Inside Logo, Intel vPro, Itanium, Itanium Inside, Intel Evo, Intel Optane, Iris, Itanium, MAX, Pentium. Dell Optiplex 780 mt ram upgrade Hi I have a option of getting a Dell Optiplex 780 mt from a good friend of mine with 8GB of ram 500GB hard drive and Windows 10 Pro I would like to upgrade it to 16GB of ram the max it supports I have a HP Compaq DC5800 that's getting old and hard to get parts for and buying a new computer. Dell. Maximum memory is 64GB on Tower/Small Form Factor, 32GB on Micro. Maximum Memory: 8GB Slots: 4. I want to upgrade my processor to the Core 2 Quad Q9650. Publish date: 20 APR 2008. Three-Step Upgrade Selector. the modern intel motherboards are almost all ATX (or proprietary). 13. Rp375. Crucial shows this as requiring 1. 2. Enter model or choose from the list below. 115 2. GX620= Pentium D or Pentium4 with 4 GIGS max DDR2 RAM = $100 or less in many places. MoBo for Dell Precision 360. Description Values. Specs say that a Core2Quad Q8200 isn't supported, but I have one running in my 755 right now. I have an Optiplex 760 x-64 running Win10 Pro that's using up 71-85% of memory with minimal applications (email, Adobe Reader, Win Office, etc. Memory Type: DDR2 PC2-8500, DDR2 PC2-6400, DDR2 PC2-5300, DDR2 (non-ECC) Maximum Memory: 8GB. May 18, 2016 at 9:17. Best choice memory for Dell Optiplex 755. Crucial Memory and SSD upgrades - 100% Compatibility Guaranteed for Dell OptiPlex 755 Series (Desktop Mini-Tower and Small Form Factor) - FREE US Delivery. Optiplex 7010 memory question. Data Security and Recovery with RAID 1 support ensures real time redundancy for data - helping to keep your business. System Model OptiPlex 755. I have recently acquired a Optiplex 755 DT. The GPU's coming with the optiplex are ***. 4x4GB DDR3-1600MHz 1. Hi, I have Dell Optiplex 755 DT model. A seagate 500GB HDD and (originally) 4GB of Samsung PC2-5300U DDR2 ram in a 4x1 configuration. 83GHz Yorkfield Quad Core Q9550 12MB, 1333FSB, E0. Dell Support Forums: Dell Desktops Forum: Dell Desktops Community Support Forums all models: Max processor and ram for the Mini-tower optiplex 755 (BIOS A17)DELL™ optipLEx™ 755Optiplex 755 DT Hardware Upgrade. ) cpu for 755 is core 2 duo and may upgrade to core 2 quad depending on motherboard Dell DP/N. First thing is to replace CMOs battery with new one ($1-2). They both came with 2 x 1GB Hynix PC2-5300U. 35 V operation for memory. OptiPlex 3090 Small Form Factor. 5 volt memory. 4GB Stick for Dell Optiplex Series 990 (Mini Tower) 990 (Small Form Factor) 990 (Ultra Small Form Factor). Tangerang Selatan ICA JAYA MANDIRI. O. Kingston Value Brand (KVR) almost never works. Another one unsupported by Dell for the 755 - core 2 quad Q9650. I also Googled and ran across this thread. Hi, I recently purchased a new Dell Optiplex 755 with an E6750 2. The memory will run at a lower PC2-6400 (or PC2-5300) speed on such a system. Memory slots Four UDIMM slots Memory type Dual-channel DDR4 Memory speed 3200 MHz Maximum memory configuration 128 GB. - no new coolers are needed. GPU - NVIDIA GT 240. System Model: OptiPlex 755 BIOS: Phoenix ROM BIOS PLUS Version 1. To get the max out of my 755 MT: CPU = C2Q Q9650; RAM = 8GB; OS is on a Crucial SSD. 28-06-2021 17:00 PM. Are you sure I don't need a new power supply? I got the Ram and Hard drive covered now, so i don't need to worry about that, neither the CPU. Monroville Dell Poweredge R715 server. model 0HX555 revision unknown serial . 5 out of 5 stars 15. A-Tech 8GB (4X 2GB) Max Memory RAM Kit for Dell OptiPlex 755, 745, 740, (MT, DT, SFF) - DDR2 667MHz PC2-5300 Non-ECC DIMM Upgrade 667 MHz 240-Pin 4. 30,340. luiscarlos. 2GB 240-pin PC2-5300 DDR2-667 non-ECC non-Registered DIMM. That's why higher than 8GB is unsupported and companies, like Crucial, that make RAM, will tell you the highest is 8GB. Graphics. Computer Specs: Processor: Intel (R) Core (TM) i5-2400 CPU @ 3. $37. Kisianik, you said a 750 ti would be appropriate for Dell Optiplex 755. This is just a guess though I am not Dell engineering and I don't have a Cpu to test. Sep 15, 2016. The NVIDIA Quadro K620 offers impressive power-efficient 3D application performance and capability. 1,510. ram can upgrade to 4x2 gb ddr2. I used the specs as specified in the manual to purchase Crucial DDR5 CT2K16G48C40U5. Crucial Memory and SSD upgrades - 100% Compatibility Guaranteed for Dell OptiPlex 745 Series (Desktop Mini-Tower and Small Form Factor) - FREE US Delivery. OptiPlex Desktops & All-in-Ones; Inspiron Desktops & All-in-Ones. The entire 8GB memory range is available to 64 -bit operating systems. Model Comments: Machine name: Dell Optiplex 755 MiniTower CPU options: - Intel Core 2 Quad (1066MHz FSB) - Intel Core 2 Duo (1333MHz FSB) - Intel Core 2 Duo (800MHz FSB) - Intel Pentium (800MHz FSB) - Intel Celeron (800MHz FSB) Chipset: Intel Q35 Express Chipset HD Bus: SATA II (7200RPM) Front. Thank You for your support! Community Dell. OptiPlex Desktop Computers - OptiPlex business desktop computers offer space-saving features, advanced security, manageability and are a choice for everyday commercial. Device Management. ) - it is much slower than when first purchased. My OptiPlex came with licenses for Windows XP and Vista, but I can't find the product key for XP. CMS 2GB (1X2GB) DDR2 5300 667MHZ Non ECC DIMM Memory Ram Upgrade Compatible with Dell® Optiplex 210L 320 330 740 745 755 Memory Ram Upgrade - A89 4. Community Dell. The 780 has socket type LGA775. 667-MHz or 800-MHz DDR2 SDRAM. Solution dextermat Nov 22, 2016 Should be 16 gb max source :more info here You have to choose between 2 x 8 gb ddr2 OR ddr3 because you cannot mix them. I would like to get input from other people that use the Optiplex 755 and get some input on what they recommend upgrading on the system to make it more of a personal.