站上網友提供的方法，只需下載軟體後，在DOS下改，今天終於變成X800XT也顯示16管了。
改完後顯卡的GPU和記憶體時脈也從X800 PRO的450mhz core / 475mhz memory變成預設值X800XT的520mhz core / 560mhz memory
但是英文說明多開四管後，因怕太熱頻率要調降，我也將GPU和MEM調降一些變500/540，能軟改開管的好像只有256MB VIVO這系列的，剩下的X800其它系列好像不一定成功!!

參考的網頁：http://myhard.yesky.com/33/1829533.shtml
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刷新顯卡之前一定要備份好原卡的Bios，以防不測！
一、備份原卡Bios（軟碟A）
　　1．執行Flasher+Floppy2.37.exe來創建一張帶有FLashRom的啟動軟碟；
　　2．用這張軟碟重新引導系統，進入Dos；
　　3．進入Dos後在“A:”狀態下鍵入如下字元來備份原卡Bios：
flashrom -s 0 backup.bin

　　現在這張包含刷新程式和原卡Bios的軟碟製作完成了，將它收好，因為以後可能會用到。
　　4．將軟碟取出重新啟動電腦。
二、刷新成Gigabyte X800XT以打開剩餘4條管線（軟碟B）
　　1．執行DrDos來創建一張的啟動軟碟；
　　2．將Gigabyte Flash utility和X800 XT BIOS解壓到這張軟碟上；
　　3．用這張軟碟重新引導系統，進入Dos；
　　．進入Dos後在“A:”狀態下鍵入如下字元刷新顯卡：
GVF11 -p -f A:\r80x256v.f1
　　5．將軟碟取出重新啟動電腦。
三、刷新原廠X800 XT Bios提高頻率（軟碟A）
　　1．將第一步製作好的軟碟A放入軟盤機；
　　2．將公版ATI X800 XT BIOS——X800XT.bin拷貝到軟碟中；
　　3．用這張軟碟重新引導系統，進入Dos；
　　4．進入Dos後在“A:”狀態下鍵入如下字元刷新顯卡：
flashrom -p -f 0 X800XT.bin
　　5．將軟碟取出重新啟動電腦。
　　將兩張軟碟收好以備後用，到此為止整個刷新過程完畢。現在你的X800 Pro VIVO已經完完全全變成一個520MHz/560MHz的X800 XT了！

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Equipment & files required
2 x floppy discs
DrDos boot disk creator: HERE
FlashROM 2.37 + floppy creator: HERE
Gigabyte Flash utility & X800 XT BIOS: HERE
Retail ATI X800 XT BIOS: HERE
**BEFORE FLASHING THE BIOS, MAKE SURE YOU MAKE A BACKUP OF YOUR OLD ONE**
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To back up your BIOS: (Floppy 'A')

(a) Create a bootable floppy disc with flashrom on it by double clicking the Flasher+Floppy2.37.exe.
(b) Restart the PC with the floppy disc inserted & boot in DOS.
(c) Once activity has ceased you will be at the A:\ prompt, type the following command line to back up your existing BIOS:
flashrom -s 0 backup.bin
You now have a file on the floppy disc named 'backup.bin' this is your original BIOS which you may require at a later date.
(d) Remove the floppy disc & reboot the PC.
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To flash to the Gigabyte X800XT BIOS for enabling the 4 locked pipelines (Floppy 'B')
(a) Create a bootable floppy disc by double clicking the DrDos boot disc creator.
(b) Unzip the Gigabyte Flash utility & X800 XT BIOS, then place the files on the floppy disc.
(c) Restart the PC with the floppy disc inserted & boot in DOS.
(d) Once activity has ceased you will be at the A:\ prompt, type the following command line to flash the BIOS:
GVF11 -p -f A:\r80x256v.f1

(e) Remove the floppy disc & reboot the PC.
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To flash to the ATI Retail X800 XT BIOS, for improved over clock (Floppy 'A')
(a) Insert floppy disc 'A' into into the floppy drive (leaving existing files in tact).
(b) Place the downloaded Retail ATI X800 XT BIOS ( X800XT.bin ) on to the floppy.
(c) Restart the PC with the floppy disc inserted & boot in DOS.
(d) Once activity has ceased you will be at the A:\ prompt, type the following command line to flash the BIOS:
flashrom -p -f 0 X800XT.bin
(e) Remove the floppy disc & reboot the PC.
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I recommend you retain the 2 floppy discs for future use.
If you have followed the instructions carefully you should have a fully fledged ATI Radeon X800 XT 520mhz core / 560mhz memory.
Due to the heat generated by the additional 4 pipelines your maximum core over clock is likely to be reduced by on average 20mhz.