$400 gáming PC

[mrpizzaface]

my prefrence is amd , I wont need or want a optical drive, or an os (I'm going to be putting a copy of WIN 8.1), I use pcpartpicker so that would help if it was on there, and I'm looking to play BF4 med/low at~40-60 fps also I would appericate a quadrant core "I don't mind used parts asking as it isn't ebay" I also have a 320 gig hdd I will use but I would like a secondary drive dosent need to be big, oh and a wifi card

 

[Jake Wenta]

For BF4, I think you'll need to step your budget up a little:
PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD FX-4350 4.2GHz Quad-Core Processor ($109.98 @ OutletPC)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: ASRock 960GM/U3S3 FX Micro ATX AM3+ Motherboard ($54.99 @ Amazon)
Memory: G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory ($63.75 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.65 @ OutletPC)
Video Card: MSI Radeon HD 7750 2GB Video Card ($79.98 @ OutletPC)
Case: Antec One ATX Mid Tower Case ($34.99 @ Newegg)
Power Supply: OCZ ZT 650W 80 PLUS Bronze Certified ATX12V Power Supply ($69.99 @ Microcenter)
Total: $503.31
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-11-07 19:22 EST-0500)

These builds can also give you some options:
http://www.tomshardware.com/forum/id-1868129/bestconfigs-poll-budget-amd-based-gaming.html

 

[dottorrent]

You are going to need another $100 for even a moderately decent budget BF4 rig, so here is one for you -

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($117.97 @ SuperBiiz)
CPU Cooler: Arctic Cooling Freezer 7 Pro Rev.2 45.0 CFM Fluid Dynamic Bearing CPU Cooler ($22.99 @ Mwave)
Motherboard: Gigabyte GA-78LMT-USB3 Micro ATX AM3+ Motherboard ($49.99 @ Newegg)
Memory: Patriot Viper 3 8GB (2 x 4GB) DDR3-1600 Memory ($65.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.65 @ OutletPC)
Video Card: MSI Radeon HD 7790 1GB Video Card ($79.99 @ Newegg)
Case: Antec One ATX Mid Tower Case ($34.99 @ Newegg)
Power Supply: XFX 550W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($55.98 @ Newegg)
Total: $487.55
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-11-07 20:43 EST-0500)