Dell OptiPlex 990 USFF case front and back pannel

Dell OptiPlex 990 USFF

Specification and Upgrade Options

The Dell OptiPlex 990 USFF is a pre-built business desktop computer first released in 2011. Although more than five years old, it is still a viable solution for home and office. The motherboard is using the Q67 chipset and supports 2th gen Intel Core processor, 8GB of DIMM DDR3-1333 memory. Because of its size, this model cannot be properly upgraded for gaming.

Dell OptiPlex 990 USFF is a Ultra Small form factor computer. Ultra Small Form Factor (USFF) computers are useful when you are low on space. This form factor is not so popular anymore and has been superseded by the Micro. As expected, free space inside those machines is extremely limited. Swapping components is of course easy, but adding something more powerful is not an option due to reduced cooling.


Form factorUltra Small
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;
Dedicated GPU *N.A.
RAM slots2
RAM speed1333 MT/s
RAM max8 GB
USB ports(7x)USB-A 2.0;
Video portsDisplayPort 1.2; VGA;
Other portsRJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;
Optional portsN.A.
SATA ports2
PCI slotsN.A.
M.2 slotsN.A.
Drive bays2.5in; 5.25in(slim);
PSU200 W
Weight3.27 kg (7.20 lb)
Price**Check Price

* Dedicated GPU warning: Check if your particular power supply model has enough power. Additionally some PSUs don't come with an auxiliary PCIe power connector and you may need to buy a SATA to PCIe power adapter.
** As an Amazon associate we earn from qualifying purchases.

Can you upgrade Dell OptiPlex 990 USFF to play games?

Dell OptiPlex 990 USFF is a business desktop computer in micro form factor. It is using a processor that provides both the CPU and GPU functionality. While integrated GPUs are sufficient for basic gaming, they are not powerful enough to run demanding games. Dell OptiPlex 990 USFF has no space for dedicated graphics card.

Micro desktop machines like Dell OptiPlex 990 USFF are usually used as home theater PCs (HTPC), in home lab projects or a as home automation servers.

Please explore the sections bellow to find ideas and suggestions on how to upgrade Dell OptiPlex 990 USFF.

Windows 11 compatibility

No, Dell OptiPlex 990 USFF does not meet the Windows 11 hardware requirements. According to Windows 11 specification, all models with Intel 7th Gen CPU or older are not officially supported. Processor with TPM 2.0 and a UEFI Secure boot BIOS is also required in order to upgrade from Windows 10 to Windows 11 through Windows Update.

However, anyone with PC that does not pass the upgrade test can download the official Windows 11 ISO, make a bootable flash drive, and install the OS manually.

GPU upgrade

It is not possible to upgrade Dell OptiPlex 990 USFF with a dedicated GPU due to the lack of space and absence of a PCIe slot. However, you can still use the integrated graphics processor for gaming. There are number of games you can enjoy with an Intel HD and UHD iGPU.


The Dell OptiPlex 990 USFF supports Gen2 Intel Core technology. Intel introduced their second generation micro architecture named Sandy Bridge in 2011. The maximum number of cores is 6 (on an i7 processor). Desktops use the 1155 LGA socket and DDR3-1066 RAM. The second generation of Intel Core is old but still sufficient for office, home tasks and retro gaming. If you plan to enjoy more recent games, a more recent CPU is required.

Best CPUs for Dell OptiPlex 990 USFF upgrade:

Model Cores (Threads) Base frequency Turbo
Core i5 2500 4(8) 3.3 GHz 3.7 GHz
Core i7 2600 4(8) 3.4 GHz 3.8 GHz
Core i7 2700K 4(8) 3.5 GHz 3.9 GHz


Dell OptiPlex 990 USFF has two RAM slots. This is more than enough for most users. For those of you who need extra flexibility and RAM size, go for a model with 4 memory slots.

To cover the needs of your OS, games, and apps, Dell OptiPlex 990 USFF supports up to 8 GB of DIMM DDR3-1333 RAM. For office work, home use, and light gaming we recommend 8GB of RAM. For everything else, use 16GB or more.

Faster RAM speeds permit your processor to access the data stored inside the memory faster. This is important for the overall speed of your system. The motherboard of the Dell OptiPlex 990 USFF supports RAM speeds of up to 1333 MT/s.

Wi-Fi Support

Dell OptiPlex 990 USFF doesn't come with any on-board Wi-Fi support. In that case, you have two options to upgrade this model with Wi-Fi. You either use an external USB Wi-Fi adapter (wireless network dongle) or a PCIe-based wireless adapter.

The USB dongle is much more convenient and easy to install, but has less space for a decent antenna and can have thermal problems. On the other hand, the PCIe based adapter is much more powerful, more reliable, and has better antenna, but it is harder to install.

Wi-Fi and Bluetooth wireless adapter upgrades for Dell OptiPlex 990 USFF:

Model Speed Frequency Interface
WiFi 6E (Gig+) Kit 3000 Mbit/s 2.4GHz / 5GHz NGFF M.2 A/E Key
Rekong AX210 3000 Mbit/s 2.4GHz / 5GHz NGFF M.2 A/E Key
Gigabyte GC-Wbax200 2400 Mbit/s 2.4GHz / 5GHz PCIe
TP-Link Archer TX50E 2400 Mbit/s 2.4GHz / 5GHz PCIe
TP-Link Archer T9UH 1300 Mbit/s 2.4GHz / 5GHz USB 3.0


Ports are important and often people don't think about them when buying a PC. For example, if you don't have enough USB ports, using external devices becomes problematic. Before you buy any system, considering your use case, check the number of external devices you are going to use and plan the number of the extension ports accordingly.

USB ports

The Dell OptiPlex 990 USFF comes with seven USB ports in total. Having more USB ports is always better, but also pay attention to the version of those USB ports. Higher version ports support faster transfer speeds. Unfortunately, this model doesn't come with a USB 3.1 port. If you need a faster connection for your peripherals, like external Solid State Drive, you will need to choose another model.

Video ports

The DisplayPort (DP) is the most widely used digital interface for transmitting digital video and audio between display devices and PCs. It is good to see that the Dell OptiPlex 990 USFF is featuring a DisplayPort 1.2. The post version is important if you target higher resolutions with high refresh rate. Although, ver. 1.2 is completely fine for most users, if possible, aim for the higher versions DisplayPort.

The HDMI port is another digital video port you can use to connect external display. It has very similar capabilities to the DisplayPort with few exceptions. However, the Dell OptiPlex 990 USFF doesn't have one. This is not a problem if there is on-board DisplayPort.

*Please keep in mind in order to use the video ports available through the motherboard, you need a CPU with integrated graphics card. If you have a dedicated GPU, use his ports instead.

SSD storage - M.2 sockets and SATA ports

The SATA port is one of the places where you can connect a stora gedevice. The Dell OptiPlex 990 USFF comes with two SATA port(s). Not enough SATA ports might limit your options for additional storage devices. Think about your use case and decide if the SATA ports provided by this model will be sufficient.

Unfortunately, the Dell OptiPlex 990 USFF has no M.2 PCIe soket and you have to rely on the available SATA ports to connect your drives.

The M.2 PCIe SSD connector in combination with an NVMe drive allows for higher transfer rates, compared to the old SATA interface. In some situations, NVMe device connected to the M.2 PCIe socket can be more than 5 times faster.

Power Supply

The Dell OptiPlex 990 USFF comes with a 200 Watt PSU. Having a power supply with high power rating is important, especially if you are doing upgrade with addtional components, like dedicated GPU and more HDDs. Will this 200 W be enough, it all depends on your specific use. Please keep in mind that some models might have more than one PSU option. Whenever possible get the most powerful one, as it might make future upgrades easier.


Dell_OptiPlex_990_USFF_motherboard.jpg motherboard layout