diff --git a/src/i830_gtf.c b/src/i830_gtf.c
index 2eff46a9..663a2f45 100644
--- a/src/i830_gtf.c
+++ b/src/i830_gtf.c
@@ -45,6 +45,7 @@
 #include "vbe.h"
 #include "vbeModes.h"
 #include "i830.h"
+#include "i830_xf86Modes.h"
 
 #include <math.h>
 
@@ -97,7 +98,6 @@ i830GetGTF(int h_pixels, int v_lines, float freq, int interlaced, int margins)
     float h_sync;
     float h_front_porch;
     float v_odd_front_porch_lines;
-    char modename[20];
     DisplayModePtr m;
 
     m = xnfcalloc(sizeof(DisplayModeRec), 1);
@@ -349,8 +349,7 @@ i830GetGTF(int h_pixels, int v_lines, float freq, int interlaced, int margins)
     m->HSync = h_freq;
     m->VRefresh = v_frame_rate /* freq */;
 
-    snprintf(modename, sizeof(modename), "%dx%d", m->HDisplay,m->VDisplay);
-    m->name = xnfstrdup(modename);
+    i830xf86SetModeDefaultName(m);
 
     return (m);
 }
diff --git a/src/i830_modes.c b/src/i830_modes.c
index ac25864c..90bd0931 100644
--- a/src/i830_modes.c
+++ b/src/i830_modes.c
@@ -176,7 +176,11 @@ I830DuplicateMode(DisplayModePtr pMode)
     *pNew = *pMode;
     pNew->next = NULL;
     pNew->prev = NULL;
-    pNew->name = xnfstrdup(pMode->name);
+    if (pNew->name == NULL) {
+	i830xf86SetModeDefaultName(pMode);
+    } else {
+	pNew->name = xnfstrdup(pMode->name);
+    }
 
     return pNew;
 }
@@ -242,6 +246,7 @@ I830GetVESAEstablishedMode(ScrnInfoPtr pScrn, int i)
 	    fabs(i830xf86ModeVRefresh(pMode) - est_timings[i].refresh) < 1.0)
 	{
 	    DisplayModePtr pNew = I830DuplicateMode(pMode);
+	    i830xf86SetModeDefaultName(pNew);
 	    pNew->VRefresh = i830xf86ModeVRefresh(pMode);
 	    return pNew;
 	}
@@ -257,7 +262,6 @@ i830GetDDCModes(ScrnInfoPtr pScrn, xf86MonPtr ddc)
     DisplayModePtr  first = NULL;
     int             count = 0;
     int             j, tmp;
-    char            stmp[32];
 
     if (ddc == NULL)
 	return NULL;
@@ -276,10 +280,6 @@ i830GetDDCModes(ScrnInfoPtr pScrn, xf86MonPtr ddc)
 	    new->HDisplay   = d_timings->h_active;
 	    new->VDisplay   = d_timings->v_active;
 
-	    sprintf(stmp, "%dx%d", new->HDisplay, new->VDisplay);
-	    new->name       = xnfalloc(strlen(stmp) + 1);
-	    strcpy(new->name, stmp);
-
 	    new->HTotal     = new->HDisplay + d_timings->h_blanking;
 	    new->HSyncStart = new->HDisplay + d_timings->h_sync_off;
 	    new->HSyncEnd   = new->HSyncStart + d_timings->h_sync_width;
@@ -291,6 +291,8 @@ i830GetDDCModes(ScrnInfoPtr pScrn, xf86MonPtr ddc)
 	    new->status     = MODE_OK;
 	    new->type       = M_T_DEFAULT;
 
+	    i830xf86SetModeDefaultName(new);
+
 	    if (d_timings->sync == 3) {
 		switch (d_timings->misc) {
 		case 0: new->Flags |= V_NHSYNC | V_NVSYNC; break;
@@ -806,6 +808,11 @@ I830ReprobePipeModeList(ScrnInfoPtr pScrn, int pipe)
 
 	i830xf86PruneInvalidModes(pScrn, &pI830->pipeMon[pipe]->Modes, TRUE);
 
+	/* silently prune modes down to ones matching the user's configuration.
+	 */
+	i830xf86ValidateModesUserConfig(pScrn, pI830->pipeMon[pipe]->Modes);
+	i830xf86PruneInvalidModes(pScrn, &pI830->pipeMon[pipe]->Modes, FALSE);
+
 	for (pMode = pI830->pipeMon[pipe]->Modes; pMode != NULL;
 	     pMode = pMode->next)
 	{
diff --git a/src/i830_xf86Modes.c b/src/i830_xf86Modes.c
index 4c5de4d9..8c34053c 100644
--- a/src/i830_xf86Modes.c
+++ b/src/i830_xf86Modes.c
@@ -1,3 +1,4 @@
+/* -*- c-basic-offset: 4 -*- */
 /* $XdotOrg: xserver/xorg/hw/xfree86/common/xf86Mode.c,v 1.10 2006/03/07 16:00:57 libv Exp $ */
 /* $XFree86: xc/programs/Xserver/hw/xfree86/common/xf86Mode.c,v 1.69 2003/10/08 14:58:28 dawes Exp $ */
 /*
@@ -87,6 +88,22 @@ i830xf86ModeVRefresh(DisplayModePtr mode)
     return refresh;
 }
 
+/**
+ * Sets a default mode name of <width>x<height>x<refresh> on a mode.
+ *
+ * The refresh rate doesn't contain decimals, as that's expected to be
+ * unimportant from the user's perspective for non-custom modelines.
+ */
+void
+i830xf86SetModeDefaultName(DisplayModePtr mode)
+{
+    if (mode->name != NULL)
+	xfree(mode->name);
+
+    mode->name = XNFprintf("%dx%dx%.0f", mode->HDisplay, mode->VDisplay,
+			   i830xf86ModeVRefresh(mode));
+}
+
 /*
  * I830xf86SetModeCrtc
  *
@@ -385,6 +402,45 @@ i830xf86ValidateModesClocks(ScrnInfoPtr pScrn, DisplayModePtr modeList,
     }
 }
 
+/**
+ * If the user has specified a set of mode names to use, mark as bad any modes
+ * not listed.
+ *
+ * The user mode names specified are prefixes to names of modes, so "1024x768"
+ * will match modes named "1024x768", "1024x768x75", "1024x768-good", but
+ * "1024x768x75" would only match "1024x768x75" from that list.
+ *
+ * MODE_BAD is used as the rejection flag, for lack of a better flag.
+ *
+ * \param modeList doubly-linked or circular list of modes.
+ *
+ * This is not in xf86Modes.c, but would be part of the proposed new API.
+ */
+void
+i830xf86ValidateModesUserConfig(ScrnInfoPtr pScrn, DisplayModePtr modeList)
+{
+    DisplayModePtr mode;
+
+    if (pScrn->display->modes[0] == NULL)
+	return;
+
+    for (mode = modeList; mode != NULL; mode = mode->next) {
+	int i;
+	Bool good = FALSE;
+
+	for (i = 0; pScrn->display->modes[i] != NULL; i++) {
+	    if (strncmp(pScrn->display->modes[i], mode->name,
+			strlen(pScrn->display->modes[i])) == 0) {
+		good = TRUE;
+		break;
+	    }
+	}
+	if (!good)
+	    mode->status = MODE_BAD;
+    }
+}
+
+
 /**
  * Frees any modes from the list with a status other than MODE_OK.
  *
diff --git a/src/i830_xf86Modes.h b/src/i830_xf86Modes.h
index 855aa460..0cba8874 100644
--- a/src/i830_xf86Modes.h
+++ b/src/i830_xf86Modes.h
@@ -31,6 +31,9 @@ i830xf86ModeHSync(DisplayModePtr mode);
 double
 i830xf86ModeVRefresh(DisplayModePtr mode);
 
+void
+i830xf86SetModeDefaultName(DisplayModePtr mode);
+
 void
 I830xf86SetModeCrtc(DisplayModePtr p, int adjustFlags);
 
@@ -61,6 +64,9 @@ void
 i830xf86ValidateModesFlags(ScrnInfoPtr pScrn, DisplayModePtr modeList,
 			    int flags);
 
+void
+i830xf86ValidateModesUserConfig(ScrnInfoPtr pScrn, DisplayModePtr modeList);
+
 void
 PrintModeline(int scrnIndex,DisplayModePtr mode);