diff --git a/src/i830.h b/src/i830.h
index 5fb7e24..b2f6c30 100644
--- a/src/i830.h
+++ b/src/i830.h
@@ -989,4 +989,14 @@ extern const int I830CopyROP[16];
 #define QUIRK_PFIT_SAFE			0x00000040
 extern void i830_fixup_devices(ScrnInfoPtr);
 
+static inline Bool
+i830_overlay_supported(ScrnInfoPtr pScrn)
+{
+    I830Ptr pI830 = I830PTR(pScrn);
+    if (!OVERLAY_NOEXIST(pI830) && pScrn->bitsPerPixel != 8 &&
+	    pI830->overlay_regs != NULL)
+	return TRUE;
+    else
+	return FALSE;
+}
 #endif /* _I830_H_ */
diff --git a/src/i830_display.c b/src/i830_display.c
index ed49fb0..ebc2235 100644
--- a/src/i830_display.c
+++ b/src/i830_display.c
@@ -1116,9 +1116,12 @@ i830_update_dsparb(ScrnInfoPtr pScrn)
   /*
     * FIFO entries will be split based on programmed modes
     */
-   if (IS_I965GM(pI830) || IS_GM45(pI830))
+   if (IS_I965GM(pI830)) {
        fifo_entries = 127;
-   else if (IS_I9XX(pI830))
+       /* we should leave ram space for plane C (overlay) */
+       if (pI830->XvEnabled && i830_overlay_supported(pScrn))
+	   fifo_entries -= 37;
+   } else if (IS_I9XX(pI830))
        fifo_entries = 95;
    else if (IS_MOBILE(pI830)) {
        fifo_entries = 255;
diff --git a/src/i830_video.c b/src/i830_video.c
index 6645daa..a4482b6 100644
--- a/src/i830_video.c
+++ b/src/i830_video.c
@@ -620,8 +620,7 @@ I830InitVideo(ScreenPtr pScreen)
     }
 
     /* Set up overlay video if we can do it at this depth. */
-    if (!OVERLAY_NOEXIST(pI830) && pScrn->bitsPerPixel != 8 &&
-	    pI830->overlay_regs != NULL)
+    if (i830_overlay_supported(pScrn))
     {
 	overlayAdaptor = I830SetupImageVideoOverlay(pScreen);
 	if (overlayAdaptor != NULL) {