Pooslipper,
Autodesk publishes recommended / certified hardware / system lists for their software. Inventor actually has three or four levels depending on whether it's free standing or part of a suite and the orientation of the suite. In general, my inclination is to follow the GPU's that are certified because using others may lessen Autodesk's support if there are problems. If you have instability in rendering or simulations, the non-certified card gets blamed. In the certified list for Inventor 2016, the GPU's are all workstation cards- Quadros and Firepros:
http://usa.autodesk.com/adsk/servlet/syscert?siteID=123112&id=18844534&results=1&stype=graphic&product_group=12&release=2016&os=8192&manuf=all&opt=2
"Recommended":
http://usa.autodesk.com/adsk/servlet/syscert?siteID=123112&id=18844534&results=1&stype=graphic&product_group=12&release=2016&os=8192&manuf=all&opt=1
"All" cards that will work:
http://usa.autodesk.com/adsk/servlet/syscert?siteID=123112&id=18844534&results=1&stype=graphic&product_group=12&release=2016&os=8192&manuf=all&opt=0
And in those three lists, the only mentions that are not Quadros or Firepros is the Intel P-series (Pro) Integrated graphics.
The systems listed are similarly workstationcentric:
http://usa.autodesk.com/adsk/servlet/syscert?siteID=123112&id=18844534&results=1&stype=system&product_group=12&release=2016&os=8192&manuf=all&opt=1
> all Dell Precisions, Lenovo Thinkstations, and HP z-series.
A pattern seems to developing.
If you're using an Inventor version with simulation, I'd recommend an LGA2011-3 (Xeon E5) > ECC > Quadro system. the recent- (1 year) Kepler series GPU's are very good, and in only a week or so (8 September.15) , there will be two new Maxwell GPU's, the M4000 and M5000, both GM204GL 256-bit and 8 GB and with 1664 and 2048 CUDA cores. the specifications that are know suggest that the M4000- which will be the same price as the K4200 - about $800 in the US- may well perform at a similar level to the K5200 which is to say it can do anything and that would include games. I use a K4200 (4GB) and the 3D results in Passmark are very good- similar to GTX 960.
As for the CPU, one of the best values in workstation CPU's has been the various versions of the Xeon E5-1650- these are 6-core and the current v3 is 3.5 /3.8GHz:
http://ark.intel.com/products/82765/Intel-Xeon-Processor-E5-1650-v3-15M-Cache-3_50-GHz
For stability, precision, multi-core rendering, to support multi-lighting sources, high anti-aliasing, and viewports, I'd suggest a Xeon E5-1650 v3 > X99 (possibly ASUS X99 WS > DDR4-2133> Quadro M4000 > M.2 SSD OS /Applications /mech'l storage.
To demonstrate the idea, here's a system concept from a few weeks ago, with prices from US sources and then in Scan and Amazon UK:
BambiBoom PixelCannon Cadamodarendergrapharific iWork TurboBlast ExtremeSignature SuperModel 8000 ®©$$™®£™©™_ 8.6.15
1. CPU: Intel Xeon E5-1650 v3 Six-Core Processor 3.5 / 3.8GHz 0GT/s 15MB LGA 2011-v3 CPU> $575 > £614 (Amazon.uk)
http://ark.intel.com/products/82765/Intel-Xeon-Processor-E5-1650-v3-15M-Cache-3_50-GHz
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http://ark.intel.com/products/82765/Intel-Xeon-Processor-E5-1650-v3-15M-Cache-3_50-GHz
http://www.superbiiz.com/detail.php?name=E51650V3BX
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http://www.amazon.com/XEON-E5-1650V3-6C-3-5G-15MB/dp/B00MU045JU/ref=sr_1_1?ie=UTF8&qid=1411580728&sr=8-1&keywords=E5-1650+v3
2. Cooler Master Hyper 212 EVO CPU cooler > $31. (£26.05 Scan.UK)
3. Motherboard: Asus X99-E WS, Intel X99, S 2011-3, DDR4, SATA III 6Gb/s, SATA RAID, PCIe 3.0 (x16), CEB> $499 (£391. Scan.UK))
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http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=Asus+X99-E+WS&N=-1&isNodeId=1
4. Crucial 32GB (4 x 8GB) 288-Pin DDR4 SDRAM ECC DDR4 2133 (PC4-17000) Server Memory Model CT2K8G4RFS4213 > $316 ($79 each) > £276 Scan.UK)(£69 ea)
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http://www.newegg.com/Product/Product.aspx?Item=N82E16820148854&cm_re=Crucial_8GB_288-Pin_DDR4_SDRAM_ECC_DDR4_2133-_-20-148-854-_-Product
http://www.scan.co.uk/products/8gb-crucial-ddr4-server-memory-pc4-17000-%282133%29-288-pins-ecc-unbuffered-cas-15-12v
5. GPU: PNY Quadro K4200 VCQK4200-PB 4GB 256-bit GDDR5 PCI Express 2.0 x16 Workstation Video Card > $789459 > £792 378.26 Scan.UK) ( But I would wait for the M4000 (8GB) which should have a similar cost)
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http://www.scan.co.uk/products/pny-nvidia-quadro-k4200-4gb-workstation-pcie-graphics-card-with-2xdp-dvi-plus-2-years-extended-warra
6. Samsung M.2 (2280) 850 EVO 500GB SATA SSD Solid State Drive> $113 (OS, applications, working files) > $186 > £145 (Scan.UK)
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http://www.scan.co.uk/products/500gb-samsung-850-evo-m2-%282280%29-ssd-sata3-6gb-s-samsung-mgx-3d-v-nand-read-540mb-s-write-500mb-s-97k
7. WD BLACK SERIES WD1003FZEX 1TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive> $75 (£57.18 Scan UK) (Files, Backup, System Image)
8. CORSAIR HX Series HX750 750W ATX12V 2.3 / EPS12V 2.91 SLI CrossFire 80 PLUS GOLD Certified Modular Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready> $130 £119.70 (Scan.UK)
9. Samsung SH-224DB/BEBE 24X SATA DVD±RW Internal Drive w/o Software (Black) SH-224DB $17.99
10 . Corsair Obsidian 750D Large Tower Case Black with Side Window No PSU > £124.50 Scan UK)
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http://www.scan.co.uk/products/corsair-obsidian-750d-black-full-tower-case-aluminium-steel-with-side-window-3x140mm-fans-usb-30-e-a
11. Microsoft Windows 7 Professional 64-bit w/ SP1 (1-Pack, DVD), OEM MSFQC04649 > $138.99 (£119.70 Scan U.K)
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TOTAL = £2685
To some extent with this kind of system, it's necessary to choose the more demanding use as priority. Above a certain level, content creation systems are quite different from content consumption systems. If your business is with Inventor it needs to be able to do that work well and if it runs that demanding application well enough, it will also play games reasonably well, only it will try and finish every frame completely and perfectly.
Cheers,
BambiBoom
1. HP z420 (2015) > Xeon E5-1660 v2 six-core @ 3.7 / 4.0GHz > 32GB DDR3 ECC 1866 RAM > Quadro K4200 (4GB) > Intel 730 480GB (9SSDSC2BP480G4R5) > Western Digital Black WD1003FZEX 1TB> M-Audio 192 sound card > 600W PSU> Logitech z2300 > Linksys AE3000 USB WiFi > 2X Dell Ultrasharp U2715H (2560 X 1440) > Windows 7 Professional 64 >
[ Passmark Rating = 5064 > CPU= 13989 / 2D= 819 / 3D= 4596 / Mem= 2772 / Disk= 4555] [Cinebench R15 > CPU = 1014 OpenGL= 126.59 FPS] 7.8.15
2. Dell Precision T5500 (2011) > Xeon X5680 six -core @ 3.33 / 3.6GHz, 24GB DDR3 ECC 1333 > Quadro K2200 (4GB ) > Samsung 840 250GB / WD RE4 Enterprise 1TB > M-Audio 192 sound card > Linksys WMP600N PCI WiFi > 875W PSU > Windows 7 Professional 64> HP 2711x (1920 X 1080)
[ Passmark system rating = 3490 / CPU = 9178 / 2D= 685 / 3D= 3566 / Mem= 1865 / Disk= 2122] [Cinebench 15 > CPU = 772 OpenGL= 99.72 FPS] 7.8.15