Intel i7-3920XM Extreme AW8063801009607 ユーザーズマニュアル

56

Datasheet, Volume 2

9:8

RW-L

0h

Uncore

GTT Graphics Memory Size (GGMS) 
This field is used to select the amount of Main Memory that is 

pre-allocated to support the Internal Graphics Translation Table. 

The BIOS ensures that memory is pre-allocated only when 

Internal graphics is enabled.
GSM is assumed to be a contiguous physical DRAM space with 

DSM, and BIOS needs to allocate a contiguous memory chunk. 

Hardware will derive the base of GSM from DSM only using the 

GSM size programmed in the register.
Hardware functionality in case of programming this value to 

Reserved is not ensured.
0h = No Preallocated Memory

1h = 1 MB of Preallocated Memory

2h = 2 MB of Preallocated Memory

3h = Reserved

7:3

RW-L

05h

Uncore

Graphics Mode Select (GMS) 
This field is used to select the amount of Main Memory that is 

pre-allocated to support the Internal Graphics device in VGA 

(non-linear) and Native (linear) modes. The BIOS ensures that 

memory is pre-allocated only when Internal graphics is enabled.
This register is also Intel TXT lockable.
Hardware does not clear or set any of these bits automatically 

based on IGD being disabled/enabled.
BIOS Requirement: BIOS must not set this field to 0h if IVD 

(bit 1 of this register) is 0. 

It is recommended that the 1 GB pre-allocated memory 

option be used for systems with at least 2 GB physical 

DRAM.

Encodings are as follows:
0h = 0 MB

1h = 32 MB

2h = 64 MB

3h = 96 MB

4h = 128 MB

5h = 160 MB

6h = 192 MB

7h = 224 MB

8h = 256 MB

9h = 288 MB

Ah = 320 MB

Bh = 352 MB

Ch = 384 MB

Dh = 416 MB

Eh = 448 MB

Fh = 480 MB

10h = 512 MB

11h = 1 GB

Other = Reserved