diff --git a/src/i810_reg.h b/src/i810_reg.h
index d97780f..9da258a 100644
--- a/src/i810_reg.h
+++ b/src/i810_reg.h
@@ -2105,6 +2105,8 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define DSPARB			0x70030
 #define   DSPARB_CSTART_SHIFT	7
 #define   DSPARB_BSTART_SHIFT	0
+#define   DSPARB_BEND_SHIFT	9 /* on 855 */
+#define   DSPARB_AEND_SHIFT	0
 #define DSPFW1			0x70034
 #define DSPFW2			0x70038
 #define DSPFW3			0x7003c
diff --git a/src/i830_driver.c b/src/i830_driver.c
index 1b07064..1041fe3 100644
--- a/src/i830_driver.c
+++ b/src/i830_driver.c
@@ -1963,7 +1963,16 @@ SetHWOperatingState(ScrnInfoPtr pScrn)
     * we don't use plane C at all so we can allocate all but one of the 96
     * FIFO RAM entries equally between planes A and B.
     */
-   OUTREG(DSPARB, (95 << DSPARB_CSTART_SHIFT) | (48 << DSPARB_BSTART_SHIFT));
+   if (IS_I9XX(pI830)) {
+       if (IS_I915GM(pI830) || IS_I915G(pI830))
+	   OUTREG(DSPARB, (95 << DSPARB_CSTART_SHIFT) |
+		  (48 << DSPARB_BSTART_SHIFT));
+       else
+	   OUTREG(DSPARB, (127 << DSPARB_CSTART_SHIFT) |
+		  (64 << DSPARB_BSTART_SHIFT));
+   } else {
+       OUTREG(DSPARB, 254 << DSPARB_BEND_SHIFT | 128 << DSPARB_AEND_SHIFT);
+   }
 }
 
 enum pipe {