What was your previous computer?
According to the specs and one of the reviews it has an actual Nvidea GT 640 in it. The only way to tell is to see if it actually has a card in the machine. Most of the connections will go along the edge. If there are dvi or hdmi connectors by themselves on a card that is at a 90' angle from the other connectors then the GPU is separate from the MB.
My previous pc was a Dell XPS 420 from 2008:
Operating System: Windows Vista Home Premium (6.0, Build 6002) Service Pack 2 (6002.vistasp2_gdr.130707-1535)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
System Model: Dell XPS420
BIOS: Phoenix ROM BIOS PLUS Version 1.10 A06
Processor: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz
Memory: 3326MB RAM
Page File: 3128MB used, 3748MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
DxDiag Version: 7.00.6002.18107 32bit Unicode
Display Devices
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Card name: ATI Radeon HD 2600 XT
Manufacturer: Advanced Micro Devices, Inc.
Chip type: ATI display adapter (0x9588)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_9588&SUBSYS_25421028&REV_00
Display Memory: 1657 MB
Dedicated Memory: 250 MB
Shared Memory: 1406 MB
Current Mode: 1280 x 1024 (32 bit) (60Hz)
Monitor: Generic PnP Monitor
Driver Name: aticfx32.dll,aticfx32.dll,atiumdag.dll,atidxx32.dl l,atiumdva.cap
Driver Version: 8.17.0010.1129 (English)
DDI Version: 10
BGRA Supported: Yes
Driver Attributes: Final Retail
It died about 5 days ago, and I replaced it with a new HP Pavillion (DxDiag attached).
but soon after trying the HP, I realized that it wasn't good enough. My old Dell XPS 420 actually ran Europa-Universalis IV better than the new HP.